Professor Susan Lanham-New

The human microbiota functions at the interface between diet, medication-use, lifestyle, host immune development and health; thus it is aligned closely with many of the recognised modifiable factors that influence bone mass accrual in the young, and bone maintenance and skeletal decline in older populations. While understanding of the relationship between micro-organisms and bone health is still in its infancy, two decades of broader microbiome research and discovery supports a role of the human gut microbiome in the regulation of bone metabolism and pathogenesis of osteoporosis as well as its prevention and treatment. In this paper we summarize the presented content, discussion and conclusions at a recent workshop held by the Osteoporosis and Bone Research Academy of the Royal Osteoporosis Society in October, 2020. Pre-clinical research has demonstrated biological interactions between the microbiome and bone metabolism. Furthermore, observational studies and randomized clinical trials have indicated that therapeutic manipulation of the microbiota by oral administration of probiotics may influence bone turnover and prevent bone loss in humans. Here, we provide a detailed review of the literature examining the relationship between the microbiota and bone health in animal models and in humans, as well as formulating the agenda for key research priorities required to advance this field. We also underscore the potential pitfalls in this research field that should be avoided and provide methodological recommendations to facilitate bridging the gap from promising concept to a potential cause and intervention target for osteoporosis.

The relationship between vitamin D (VitD) and insulin sensitivity and secretion in type 2 diabetes mellitus (T2D) has been shown to be different amongst different ethnic populations. In Saudi Arabia, where both T2D and VitD deficiency are highly prevalent health concerns, little is known about the relationship between VitD, insulin sensitivity, resistance and the relative importance of ethnicity. Our primary aim in this study was to investigate influence of ethnicity on VitD association with glycaemic profile and to measures of obesity as a secondary outcome, among multiethnic postmenopausal women with T2D in Saudi Arabia. A cross-sectional study was conducted at King Fahad Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia. Postmenopausal females (n = 173, age ≥ 50 years) with T2D were randomly selected in this study. Anthropometric measures and fasting blood samples were obtained for all study participants. Several biochemical parameters were measured including 25-hydroxyvitamin D (25(OH)D), glycosylated hemoglobin (HbA1c), insulin, glucose and c-peptide. Surrogate markers for insulin resistance were calculated using Homeostasis Model Assessment 2 for insulin resistance and beta cell activity (HOMA2-IR, HOMA2-β). Overall, 25(OH)D was inversely associated with fasting glucose (r=-0.165, P = 0.037), insulin (r=-0.184, P = 0.02), C-peptide (r=-0.19, P = 0.015) and HOMA2- IR C-peptide (r=-0.23, P = 0.004). Additionally, serum 25 (OH)D showed a negative correlation with body weight (r=-0.173 P = 0.028), waist and hip circumferences (r=-0.167, P = 0.033; r=-0.22, P = 0.004 respectively) but not with body mass index (BMI) or waist hip ratio (WHR). In the white ethnic group but not in black or Asian population groups, 25(OH)D level was also associated with only serum fasting C-peptide and HOMA2-IR C-peptide and BMI (P 

Vitamin D deficiency remains a global public health issue, particularly in minority ethnic groups. This review investigates the vitamin D status (as measured by 25(OH)D and dietary intake) of the African-Caribbean population globally. A systematic review was conducted by searching key databases (PUBMED, Web of Science, Scopus) from inception until October 2019. Search terms included 'Vitamin D status' and 'African-Caribbean'. A random effects and fixed effects meta-analysis was performed by combining means and standard error of the mean. The search yielded 19 papers that included n = 5670 African-Caribbean participants from six countries. A meta-analysis found this population to have sufficient (>50 nmol/L) 25(OH)D levels at 67.8 nmol/L, 95% CI (57.9, 7.6) but poor dietary intake of vitamin D at only 3.0 µg/day, 95% CI (1.67,4.31). For those living at low latitudes 'insufficient' (as defined by study authors) 25(OH)D levels were found only in participants with type 2 diabetes and in those undergoing haemodialysis. Suboptimal dietary vitamin D intake (according to the UK recommended nutrient intake of 10 µg/day) was reported in all studies at high latitudes. Studies at lower latitudes, with lower recommended dietary intakes (Caribbean recommended dietary intake: 2.5 µg/day) found 'sufficient' intake in two out of three studies. 25(OH)D sufficiency was found in African-Caribbean populations at lower latitudes. However, at higher latitudes, 25(OH)D deficiency and low dietary vitamin D intake was prevalent.

Background: The rapid global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), the virus that causes coronavirus disease 2019 (COVID-19), has re-ignited interest in the possible role of vitamin D in modulation of host responses to respiratory pathogens. Indeed, vitamin D supplementation has been proposed as a potential preventative or therapeutic strategy. Recommendations for any intervention, particularly in the context of a potentially fatal pandemic infection, should be strictly based on clinically informed appraisal of the evidence base. In this narrative review, we examine current evidence relating to vitamin D and COVID-19 and consider the most appropriate practical recommendations. Observations: Although there are a growing number of studies investigating the links between vitamin D and COVID-19, they are mostly small and observational with high risk of bias, residual confounding, and reverse causality. Extrapolation of molecular actions of 1,25(OH)2-vitamin D to an effect of increased 25(OH)-vitamin D as a result of vitamin D supplementation is generally unfounded, as is the automatic conclusion of causal mechanisms from observational studies linking low 25(OH)-vitamin D to incident disease. Efficacy is ideally demonstrated in the context of adequately powered randomised intervention studies, although such approaches may not always be feasible. Conclusions: At present, evidence to support vitamin D supplementation for the prevention or treatment of COVID-19 is inconclusive. In the absence of any further compelling data, adherence to existing national guidance on vitamin D supplementation to prevent vitamin D deficiency, predicated principally on maintaining musculoskeletal health, appears appropriate.

Background: Numerous research studies have found an association between vitamin D (vitD) status and single-nucleotide polymorphisms (SNPs) in genes involved in vitD metabolism. It is notable that the influence of these SNPs on 25-hydroxyvitamin D [25(OH)D] levels might vary in different populations. In this study, we aimed to explore for genetic variants in genes related to vitD metabolism in families with vitD deficiency in Saudi Arabia using whole-exome sequencing (WES). Methods: This family-based WES study was conducted for 21 families with vitD deficiency (n = 39) in Saudi Arabia. WES was performed for DNA samples, then resulting WES data was filtered and a number of variants were prioritized and validated by Sanger DNA sequencing. Results: Several missense variants in vitD-related genes were detected in families. We determined two variants in low-density lipoprotein 2 gene (LRP2) with one variant (rs2075252) observed in six individuals, while the other LRP2 variant (rs4667591) was detected in 13 subjects. Single variants in 7-dehydrocholesterol reductase (DHCR7) (rs143587828) and melanocortin-1 receptor (MC1R) (rs1805005) genes were observed in two subjects from two different families. Other variants in group-specific component (GC), cubilin (CUBN), and calcium-sensing receptor (CASR) gene were found in index cases and controls. Polymorphisms in GC (rs9016) and CASR (rs1801726) were found in the majority of family cases (94 and 88%), respectively. Conclusion: In vitD-deficient families in Saudi Arabia, we were able to detect a number of missense exonic variants including variants in GC (rs9016), CUBN (rs1801222), CASR (rs1801726), and LRP2 (rs4667591). However, the existence of these variants was not different between affected family members and non-affected controls. Additionally, we were able to find a mutation in DHCR7 (rs143587828) and a polymorphism in LRP2 (rs2075252), which may affect vitD levels and influence vitD status. Further studies are now required to confirm the association of these variants with vitD deficiency.

The global population is at risk of vitamin D deficiency due to low exposure to sunlight and low intake of the vitamin through diet. The aim of this study was to investigate in women the association between vitamin D status and parathyroid hormone (PTH), ultraviolet radiation, lifestyle, ethnicity, social conditions, and residential greenness. A 1-year longitudinal study assessed vitamin D status in 309 women living at latitude 51 degrees 14 ' N. Blood samples were taken four times throughout the year for analysis of 25(OH)D and serum PTH concentration. After each seasonal visit, the individuals completed 4-day diet diaries and used two dosimeter badges for 1 week to estimate weekly UVR exposure. A questionnaire was applied to provide information about lifestyle and their ethnicity. Residential greenness was measured by Normalized Difference Vegetation Index (NDVI), within a 1000 m radius around each participant's home address. Women living in greener spaces were more likely to have improved vitamin D status (RR: 1.51; 95%CI: 1.13-2.02), as well as those who were more exposed to UVR (RR: 2.05; 95%CI: 1.44-2.92). Our results provide an insight into the connection between residential greenness, lifestyle, and vitamin D status comparing two ethnicities in a country with a temperate climate and with a high degree of urbanization.

Following two requests from the European Commission (EC), the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the revision of the tolerable upper intake level (UL) for vitamin D and to propose a conversion factor (CF) for calcidiol monohydrate into vitamin D-3 for labelling purposes. Vitamin D refers to ergocalciferol (vitamin D-2), cholecalciferol (vitamin D-3), and calcidiol monohydrate. Systematic reviews of the literature were conducted to assess the relative bioavailability of calcidiol monohydrate versus vitamin D-3 on serum 25(OH)D concentrations, and for priority adverse health effects of excess vitamin D intake, namely persistent hypercalcaemia/hypercalciuria and endpoints related to musculoskeletal health (i.e. falls, bone fractures, bone mass/density and indices thereof). Based on the available evidence, the Panel proposes a CF for calcidiol monohydrates of 2.5 for labelling purposes. Persistent hypercalciuria, which may be an earlier sign of excess vitamin D than persistent hypercalcaemia, is selected as the critical endpoint on which to base the UL for vitamin D. A lowest-observed-adverse-effect-level (LOAEL) of 250 & mu;g/day is identified from two randomised controlled trials in humans, to which an uncertainty factor of 2.5 is applied to account for the absence of a no-observed-adverse-effect-level (NOAEL). A UL of 100 & mu;g vitamin D equivalents (VDE)/day is established for adults (including pregnant and lactating women) and for adolescents aged 11-17 years, as there is no reason to believe that adolescents in the phase of rapid bone formation and growth have a lower tolerance for vitamin D compared to adults. For children aged 1-10 years, a UL of 50 & mu;g VDE/day is established by considering their smaller body size. Based on available intake data, European populations are unlikely to exceed the UL, except for regular users of food supplements containing high doses of vitamin D.

Context and purpose There is an urgent need to develop vitamin D dietary recommendations for dark-skinned populations resident at high latitude. Using data from randomised controlled trials (RCTs) with vitamin D-3-supplements/fortified foods, we undertook an individual participant data-level meta-regression (IPD) analysis of the response of wintertime serum 25-hydroxyvitamin (25(OH)D) to total vitamin D intake among dark-skinned children and adults residing at >= 40 degrees N and derived dietary requirement values for vitamin D. Methods IPD analysis using data from 677 dark-skinned participants (of Black or South Asian descent; ages 5-86 years) in 10 RCTs with vitamin D supplements/fortified foods identified via a systematic review and predefined eligibility criteria. Outcome measures were vitamin D intake estimates across a range of 25(OH)D thresholds. Results To maintain serum 25(OH)D concentrations >= 25 and 30 nmol/L in 97.5% of individuals, 23.9 and 27.3 mu g/day of vitamin D, respectively, were required among South Asian and 24.1 and 33.2 mu g/day, respectively, among Black participants. Overall, our age-stratified intake estimates did not exceed age-specific Tolerable Upper Intake Levels for vitamin D. The vitamin D intake required by dark-skinned individuals to maintain 97.5% of winter 25(OH)D concentrations >= 50 nmol/L was 66.8 mu g/day. This intake predicted that the upper 2.5% of individuals could potentially achieve serum 25(OH)D concentrations >= 158 nmol/L, which has been linked to potential adverse effects in older adults in supplementation studies. Conclusions Our IPD-derived vitamin D intakes required to maintain 97.5% of winter 25(OH)D concentrations >= 25, 30 and 50 nmol/L are substantially higher than the equivalent estimates for White individuals. These requirement estimates are also higher than those currently recommended internationally by several agencies, which are based predominantly on data from Whites and derived from standard meta-regression based on aggregate data. Much more work is needed in dark-skinned populations both in the dose-response relationship and risk characterisation for health outcomes. Trail registration PROSPERO International Prospective Register of Systematic Reviews (Registration Number: CRD42018097260)

Vitamin D can be sourced from food and produced from skin exposure to sunlight.(1) In Australia and worldwide, vitamin D deficiency is highly prevalent. Data shows that 23% of the Australian population are considered to be vitamin D insufficient (25(OH)D < 50 nmol/L), increasing to 36% during the winter.(2) Current estimated average intakes do not meet dietary recommendations.(3) A lack of vitamin D, and thus reduced absorption of calcium, results in leaching of calcium stored in the bones leading to poor musculoskeletal health.(1) The aim of this study is to determine the impact that latitude, skin type, diet and sun exposure have on vitamin D status of healthy Australian women and to explore the rates and potential causes of deficiency. This cross-sectional study was conducted in Wollongong, Australia (34.42°S) during winter 2020 and spring 2021 with 100 women (> 18 years, pre- or post-menopausal). Skin types were self-defined. Serum 25(OH)D was measured through liquid chromatography mass spectrometry, dietary intake through a 4-day food record analysed using FoodWorks 10, bone density through dual energy x-ray absorptiometry and sun exposure through a polysulphone film badge worn for 4 days. Participants were aged 41.4 ± 15.5 years and 98 women had valid serum 25(OH)D measurements. Of these, n = 1 (1.0%) was deficient (< 25 nmol/L), n = 14 (14.3%) were insufficient (25–50 nmol/L) and n = 41 (41.8%) were sufficient (> 50 nmol/L), while n = 42 (42.9%) had an optimal status (> 75 nmol/L) of vitamin D. The mean 25(OH)D was significantly different across skin type groups (white compared to moderate brown skin types) (F(4,93) = 2.6, p = 0.04), whilst average sun exposure (SED) of 1.1 ± 1.0 was on the borderline of significantly predicting 25(OH)D levels (F(1, 92) = 3.74, p = 0.06). A significant positive correlation existed between 25(OH)D and total bone mineral density (r(96) = 0.27, p < 0.001). Mean vitamin D intake (n = 94) was 3.1 ± 3.0 μg/day, with the majority of participants (86.2%) having intakes below.(3) Logistic regression, controlling for age, showed that an increase in reported calcium intake (OR = 1.0, 95% CI [1.0, 1.0], p = 0.01), average SED (OR = 0.0, 95% CI [0.0, 1.3], p < 0.001) and having a lighter skin type (OR = 7.0, 95% CI [1.1, 43.3], p = 0.04) were significantly associated with reduced odds of deficiency/insufficiency. Serum 25(OH)D was found to be higher than reported in previous Australian data,(2) which is favourable given the essential role vitamin D plays in calcium homeostasis and musculoskeletal health. However, reported dietary vitamin D intakes were low. Given the increased risk of melanoma from excessive sun exposure, targeted advice towards vitamin D-rich food sources may be helpful for those individuals with poorer vitamin D status.

Optimal vitamin D status has commonly been defined as the level of 25-hydroxyvitamin D (25(OH)D) at which parathyroid hormone (PTH) concentrations would be maximally suppressed, represented by an observed minimum plateau. Previous findings indicate a large variation in this plateau, with values ranging from

Comprehensive resource on all aspects of nutrition and metabolism; covering vitamin and mineral deficiencies, diseases, immunity, brain and bone health, and more. Now in its third edition, Nutrition and Metabolism has been updated throughout to present readers with the core principles of nutrition in the context of a systems and health approach. Written by a team of internationally renowned experts, the text includes information on: - Body composition, energy metabolism, proteins, amino acids, carbohydrates, lipids, vitamins, minerals, trace elements, food intake, and food composition. - Energy, macronutrients, pregnancy and lactation, growth and aging, brain nutrition, sensory systems and food palatability, the gastrointestinal system, and the cardiovascular system. - Societal food choices, over- and undernutrition, eating disorders, dieting, foetal programming, cancer, osteoporosis, and diabetes - How nutrition affects the liver, pancreas, kidney, lungs, heart and blood vessels, and how nutrition relates to the development of traumatic, infectious, and malignant diseases. Nutrition and Metabolism is an essential resource for students and practitioners of nutrition and dietetics, as well as students majoring in other subjects that have a nutrition component.

Introduction: It has been hypothesised that the U shaped association between 25(OH)D and some health outcomes may be due to large seasonal fluctuations of 25(OH)D1. It is unknown whether such fluctuation of 25(OH)D (‘cycling’) influences bone health. Methods: In the D-FINES study, n=373 women (South Asian/Caucasian) had repeated measurements in four seasons for serum 25(OH)D and PTH. A random sample (n=66) were measured for serum C-telopeptide (CTX). Seasonal cycling of 25(OH)D was assessed as the absolute difference between winter (nadir) and summer (peak) 25(OH)D and was split into quartiles within ethnicity. Summer to winter change in CTX and PTH were calculated. Results and Discussion: ANCOVA showed no statistically significant association between quartile of cycling of 25(OH)D and CTX or PTH. However, in Asians, there was a trend for increased cycling to be associated with reduced PTH but not CTX, and for an increase in PTH from summer to winter. In Caucasians, there was a trend for increased cycling in all seasons to be associated with reduced CTX. However, increased cycling was associated with increased PTH in summer and spring, but lower PTH in other seasons, as well as a reduction in PTH from summer to winter (p=0.06). Therefore increased cycling in Caucasians was associated with lower bone resorption and was differentially associated with PTH depending on season. Further analysis of banked samples for urine CTX (n=1500) will enable these novel results to be explored further.

The present paper reviews published literature on the relationship between dietary protein and bone health. It will include arguments both for and against the anabolic and catabolic effects of dietary protein on bone health. Adequate protein intake provides the amino acids used in building and maintaining bone tissue, as well as stimulating the action of insulin-like growth factor 1, which in turn promotes bone growth and increases calcium absorption. However, the metabolism of dietary sulphur amino acids, mainly from animal protein, can lead to increased physiological acidity, which may be detrimental for bone health in the long term. Similarly, cereal foods contain dietary phytate, which in turn contains phosphate. It is known that phosphate consumption can also lead to increased physiological acidity. Therefore, cereal products may produce as much acid as do animal proteins that contain sulphur amino acids. The overall effect of dietary protein on physiological acidity, and its consequent impact on bone health, is extremely complex and somewhat controversial. The consensus is now moving towards a synthesised approach. Particularly, how anabolic and catabolic mechanisms interact; as well as how the context of the whole diet and the type of protein consumed is important.

Little research has assessed serum 25-hydroxyvitamin D (25(OH)D) concentration and its predictors in western dwelling South Asians in a relatively large sample size. This observational, cross-sectional analysis assessed baseline prevalence of 25(OH)D deficiency in UK dwelling South Asians (aged 40-69 years, 2006-2010) from the UK Biobank cohort. Serum 25(OH)D measurements were undertaken using the DiaSorin Liaison XL assay. Of n 6433 South Asians with a 25(OH)D measurement, using commonly used cut-off thresholds, 55% (n 3538) had 25(OH)D

Currently, there is a lack of clarity in the literature as to whether there is a definitive difference between the effects of vitamins D(2) and D(3) in the raising of serum 25-hydroxyvitamin D [25(OH)D].

The relative contribution of UVB sunlight exposure and dietary vitamin D intake to 25-hydroxyvitamin D (25(OH)D) remains to be fully determined. The aim of this study was to examine these factors in combination using a repeated measures multilevel modelling approach. The D-FINES study investigated 373 Surrey Caucasian and Asian women in four seasons of the year for 25(0H)D, dietary vitamin D and UVB exposure. To capitalise on the clustered nature of the repeated seasonal measurements within individuals, multilevel modelling was undertaken using MLwiN v.2.1software. Thus seasonal data (dietary vitamin D (DietaryVitD), UV exposure (UVdosi), vitamin D status (VitDstatus)) were included at level one (ij) and individual level data (ethnicity, menopausal status (0=Caucasian, 1=Asian; 0=Premenopausal, 1=Postmenopausal)) at level two (j). Using a random intercept model, the following equation was constructed, which was significantly different from an intercept only model (Log likelihood test- Chi square X2= 2216.51, df=5, p

There is an urgent need to assess risk factors affecting individual likelihood of contracting the novel SARS-CoV-2 virus, and development of COVID-19. One potential risk factor is vitamin D deficiency(Reference Lanham-New1). Vitamin D is important for immune defence against pathogens as it promotes macrophage antimicrobial responses and the regulation of antigen-presenting dendritic cells and suppressor T-cells(Reference Hewison2). However, it is unclear whether 25(OH)D concentration is associated with risk of contracting SARS-CoV-2 and/or developing COVID-19. We aimed to assess whether there is an association between serum 25(OH)D status and odds of testing positive for SARS-CoV-2, when controlling for confounders such as body mass index (BMI) and ethnicity.

Globally, there has been a marked increase in longevity, but it is also apparent that significant inequalities remain, especially the inequality related to insufficient 'health' to enjoy or at least survive those later years. The major causes include lack of access to proper nutrition and healthcare services, and often the basic information to make the personal decisions related to diet and healthcare options and opportunities. Proper nutrition can be the best predictor of a long healthy life expectancy and, conversely, when inadequate and/or improper a prognosticator of a sharply curtailed expectancy. There is a dichotomy in both developed and developing countries as their populations are experiencing the phenomenon of being 'over fed and under nourished', i.e., caloric/energy excess and lack of essential nutrients, leading to health deficiencies, skyrocketing global obesity rates, excess chronic diseases, and premature mortality. There is need for new and/or innovative approaches to promoting health as individuals' age, and for public health programs to be a proactive blessing and not an archaic status quo 'eat your vegetables' mandate. A framework for progress has been proposed and published by the World Health Organization in their Global Strategy and Action Plan on Ageing and Health (WHO (2017) Advancing the right to health: the vital role of law. https://apps.who.int/iris/bitst ream/ handle/10665/252815/ 9789241511384-eng.pdf?sequence=1&isAllowed=y. Accessed 07 Jun 2021; WHO (2020a) What is Health Promotion. www.who.int/healthpromotion/fact-sheet/en/. Accessed 07 Jun 2021; WHO (2020b) NCD mortality and morbidity. www.who.int/gho/ncd/mortality_morbidity/en/. Accessed 07 Jun 2021). Couple this WHO mandate with current academic research into the processes of ageing, and the ingredients or regimens that have shown benefit and/or promise of such benefits. Now is the time for public health policy to 'not let the perfect be the enemy of the good,' but to progressively make health-promoting nutrition recommendations.

The spread of novel SARS-CoV-2 virus, and the disease COVID-19 that is caused by SARS-CoV-2, continues apace. Saving lives and slowing the worldwide pandemic remain of utmost importance to everyone: the public, healthcare professionals, scientists, industry and governments. It is absolutely essential that advice given to the public is evidence-based, accurate and timely; anything less would mislead and has the potential to cause harm. Popular information channels, such as social media platforms, have been rife with misinformation that has been perpetuated by fear and uncertainty. This has been the case particularly for diet and lifestyle advice. There are recommendations for the prevention of the spread of COVID-19 from the WHO,1 the UK,2 Irish3 and USA4 governments and the European Commission,5 as well as public health and healthcare agencies, including key direction on self-isolation.6 This short original report aims to provide a balanced scientific view on vitamin D and SARS-CoV-2 virus/COVID-19 disease. It provides a succinct summary of the current scientific evidence of associations between vitamin D, influenza, upper respiratory tract infections (URTIs) and immune health. Importantly, the paper concludes with lifestyle strategies for avoiding vitamin D deficiency and ensuring a healthy balanced diet at any time, including during the current pandemic. The overarching messages are as follows: (1) Vitamin D is essential for good health. (2) Many people, particularly those living in northern latitudes (such as the UK, Ireland, Northern Europe, Canada and the northern parts of the USA, northern India and China), have poor vitamin D status, especially in winter or if confined indoors. (3) Low vitamin D status may be exacerbated during this COVID-19 crisis (eg, due to indoor living and hence reduced sun exposure), and anyone who is self-isolating with limited access to sunlight is advised to take a vitamin D supplement according to their government’s recommendations for the general population (ie, 400 IU/day for the UK7 and 600 IU/day for the USA (800 IU for >70 years))8 and the European Union (EU).9 (4) There is no strong scientific evidence to show that very high intakes (ie, mega supplements) of vitamin D will be beneficial in preventing or treating COVID-19. (5) There are evidenced health risks with excessive vitamin D intakes especially for those with other health issues such as a reduced kidney function.

The potential ergogenic effects of vitamin D (vitD) in high performing athletes has received considerable attention in the literature and media. However, little is known about non-supplemented university athletes and students residing at a higher latitude. This study aimed to investigate the effects of vitD (biochemical status and dietary intake) on exercise performance in UK university athletes and sedentary students. A total of 34 athletes and 16 sedentary controls were studied during the spring and summer months. Serum vitD status and sunlight exposure were assessed using LC-MS/MS and dosimetry, respectively. Muscular strength of the upper and lower body was assessed using handgrip and knee extensor dynamometry (KE). Countermovement jump (CMJ) and aerobic fitness were measured using an Optojump and VO2max test, respectively. Statistical analysis was performed using paired/ independent t-tests, ANCOVA and Pearson/ Spearman correlations, depending on normality. VitD status increased significantly over the seasons, with athletes measuring higher status both in spring (51.7 +/- 20.5 vs. 37.2 +/- 18.9 nmol/L, p = 0.03) and summer (66.7 +/- 15.8 vs 55.6 +/- 18.8 nmol/L, p = 0.04) when compared to controls, respectively. Notably, 22% of the subjects recruited were vitD deficient during the spring term only (

Vitamin D deficiency has been commonly reported in elite athletes, but the vitamin D status of UK university athletes in different training environments remains unknown. The present study aimed to determine any seasonal changes in vitamin D status among indoor and outdoor athletes, and whether there was any relationship between vitamin D status and indices of physical performance and bone health. A group of forty-seven university athletes (indoor n 22, outdoor n 25) were tested during autumn and spring for serum vitamin D status, bone health and physical performance parameters. Blood samples were analysed for serum 25-hydroxyvitamin D (s-25(OH)D) status. Peak isometric knee extensor torque using an isokinetic dynamometer and jump height was assessed using an Optojump. Aerobic capacity was estimated using the Yo-Yo intermittent recovery test. Peripheral quantitative computed tomography scans measured radial bone mineral density. Statistical analyses were performed using appropriate parametric/non-parametric testing depending on the normality of the data. s-25(OH)D significantly fell between autumn (52 center dot 8 (sd 22 center dot 0) nmol/l) and spring (31 center dot 0 (sd 16 center dot 5) nmol/l; P < 0 center dot 001). In spring, 34 % of participants were considered to be vitamin D deficient (

The primary source of vitamin D is through synthesis in the skin, following exposure to sunlight containing ultraviolet B (UVB) radiation. Supply through skin exposure can be supplemented by the diet, but there are relatively few dietary sources, especially those which provide a large amount of vitamin D per serving. Research into the effects of vitamin D status in different population groups has become an increasingly popular topic. The current interest surrounding vitamin D research in sport remains focused on the potential ergogenic effects of vitamin D on physical performance. However, the relationship between vitamin D (dietary intake and status) and musculoskeletal health in university athlete cohorts residing at higher latitudes (>40 degrees N) remains underinvestigated. Within this review, the possible physiological roles that vitamin D may play within sport performance for recreational and professional athletes, as well as military recruits, will be discussed. The focus will be on muscular strength, cardiovascular health and the incidence of illness, including upper respiratory tract infections. Specifically, the effect that vitamin D deficiency {defined as a plasma/serum 25-hydroxyvitamin D [25(OH)D] concentration of 40 degrees N) where wintertime vitamin D deficiency is prevalent. It is hoped that this review will help to raise the awareness of the importance of existing advice in the UK for the avoidance of vitamin D deficiency and international vitamin D guidelines (such as in the US) on the achievement of vitamin D sufficiency [serum 25(OH)D >50 nmol/l] for optimum health and performance in athletes, both professional and recreational.

Vitamin D is truly unique—not a ‘vital’ amine in the true sense of the word, but rather a prohormone, which is produced in the skin during exposure to sunlight (UVB radiation at 290–315 nm) and which can also be obtained from food and from supplements. A high prevalence of low vitamin D status has been reported across the world in a wide range of population groups, and this includes communities living in low latitude areas despite the abundance of sunlight. It is accepted that vitamin D status is reflected by the level of the circulating metabolite 25‐hydroxyvitamin D (25[OH]D), which is produced by hepatic hydroxylation of vitamin D, derived either from the skin from UV exposure or the gut from oral intake. Vitamin D has been associated with a wide range of health outcomes, but controversies remain as to their exact nature and extent and whether associations are in the causal pathway. In order to enable wider discussions on this nutrient, a ‘Hot Topic’ Vitamin D Workshop achieved funding from the UK Nutrition Research Partnership Medical Research Council call. The objectives of the workshop were (1) to elucidate the role of vitamin D in human health and (2) develop strategies to improve vitamin D status in the UK population. This paper provides a detailed resume of the discussions of the workshop; of the presentations and concomitant Q and of identified areas for future research.

Vitamin D deficiency may have an important role in the development of Type-2 diabetes(Reference Pittas, Dawson-Hughes, Sheehan, Ware, Knowler and Aroda1,Reference Kayaniyil, Vieth, Retnakaran, Knight, Qi and Gerstein2) . Low vitamin D concentration has broad-ranging effects that are both directly (by activation of the vitamin D receptor) and indirectly (by modulation of intracellular calcium concentration) related to impaired pancreatic β-cell function and insulin resistance(Reference Norman, Frankel, Heldt and Grodsky3). The purpose of this systematic review and meta-analysis was to examine the effect of vitamin D supplementation on insulin resistance and glycaemic control in participants with prediabetes.

Adequate intakes of the B vitamins are essential for health; however there is a lack of data concerning B vitamin intakes in UK dwelling South Asian (SA) groups. We aimed to investigate whether UK SA women meet the LRNI for B vitamins, and whether their intake differs from same-age White Caucasian (WC) women. We used summer 2006 dietary intake data from the Food Standards Agency (FSA) funded D-FINES study (Vitamin D, Food Intake, Nutrition and Exposure to Sunlight in Southern England, project N05064). After removal of over- and under-reporters (energy: BMR ratio < 1 or > 1.6) there were n = 29 SA and n = 146 WC subjects. The two groups did not differ significantly in age and BMI. Overall mean (SD) for age was 50.6 (13.6) years and for BMI was 26.8 (4.8). In SA, 41% were Bangladeshi or Pakistani, 28% were Indian and 31% were of other ethnicity. Independent T-tests, using log transformed data, showed no statistically significant differences for any B vitamin (Bonferroni revised p value: < 0.008). Results were as follows, giving median (IQR): Thiamine (mg) 1.5 (0.5) SA vs 1.4 (0.5) WC; (P = 0.8); Riboflavin (mg) 1.3 (0.5) SA vs. 1.5 (0.6) WC (P = 0.08); Niacin (mg) 30.7 (13.7) SA vs 33.3 (9.8) WC (P = 0.4); B6 (mg) 1.7 (0.5) SA vs 1.9 (0.7) WC (P = 0.2); B12 (micrograms) 2.8 (0.05) SA vs 3.6 (2.5) WC (P = 0.02); Folate (micrograms) 213 (93) SA vs 231 (82) WC (P = 0.8). In terms of percentages below the LRNI: Thiamine 0% SA and 0.7% (n = 1) WC; Riboflavin 0% SA and 1.4% (n = 2) WC; B12 10% (n = 3) SA and 0% WC. For Niacin, B6 and Folate no women in either group were below the LRNI. Overall, there were no ethnic differences in B vitamin intake by ethnicity. There was a trend for a slightly lower B12 intake in SA but this did not reach statistical significance after adjustment for multiple testing. It is of concern that 10% of SA did not meet the LRNI for B12. Of this 10%, the majority were not vegetarian or vegan. The sample size for SA was very small and further research is now required in a larger sample to confirm this finding. The D-FINES study was funded by the UK FSA (N05064). The views expressed are those of the authors alone.

A multi-disciplinary expert group met to discuss vitamin D deficiency in the UK, and strategies for improving population intakes and status. Changes to UK Government advice since the 1st Rank Forum on Vitamin D (2009) were discussed, including rationale for setting a RNI (10µg/day;400IU/day) for adults and children (4+ years). Current UK data show inadequate intakes among all age groups, and high prevalence of low vitamin D status among specific groups (e.g. pregnant women and adolescent males/females). Evidence of widespread deficiency within some minority ethnic groups, resulting in nutritional rickets (particularly among Black and South Asian infants), raised particular concern. It is too early to establish whether population vitamin D status has altered since Government recommendations changed in 2016. Vitamin D food fortification was discussed as a potential strategy to increase population intakes. Data from dose-response and dietary modelling studies indicate dairy products, bread, hens' eggs and some meats as potential fortification vehicles. Vitamin D3 appears more effective than vitamin D2 for raising serum 25-hydroxyvitamin D concentration, which has implications for choice of fortificant. Other considerations for successful fortification strategies include: i) need for 'real-world' cost information for use in modelling work; ii) supportive food legislation; iii) improved consumer and health professional understanding of vitamin D's importance; iv) clinical consequences of inadequate vitamin D status; v) consistent communication of Government advice across health/social care professions, and via the food industry. These areas urgently require further research to enable universal improvement in vitamin D intakes and status in the UK population.

Vitamin D (vitD) deficiency is highly prevalent in the Middle East (including Saudi Arabia) despite the abundance of sunlight. Older individuals in particular are at high risk of being vitD deficient. VitD binding protein (DBP), which acts as a carrier of vitD and its metabolites, has been reported to influence vitD status. In our study we aimed to investigate vitD status among postmenopausal women and its relation to DBP. A cross-sectional study was conducted at the King Fahad Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia. Seventy six postmenopausal females (age ≥ 50 years) who were not taking vitD supplementation and who were resident in Jeddah city, were randomly recruited from internal medicine clinics at King Abdulaziz University Hospital. Anthropometric measures, blood pressure, lifestyle history, dietary vitD intake and fasting blood samples were obtained from all study participants. Serum total 25 hydroxy-vitamin D (25(OH)D), DBP, albumin, parathyroid hormone, calcium, phosphate, magnesium and metabolic bone parameters were analysed. VitD deficiency was defined as serum total 25(OH)D level below 30 nmol/L. The mean (± SD) serum level of total 25(OH)D was 46.9 ± 28.9 nmol/L with 36 % of the study population being vitD deficient. Although non-significant, the vitD deficient group had lower DBP and higher dietary vitD intake levels when compared with those with serum vitD > 30nmol/L. In addition, DBP was inversely correlated with vitD dietary intake (r = -0.233, P = 0.046). In conclusion, vitD deficiency is highly prevalent among postmenopausal women living in Jeddah, Saudi Arabia. Intake of a vitD rich food seems to be associated with low DBP levels. Genetic polymorphisms in DBP will be studied in the future to find out a possible explanation for the differences in vitD status and DBP between individuals as well as the concomitant relationship between dietary vitD intake, DBP and serum 25(OH)D levels.

Background Vitamin D deficiency is a common consequence of bariatric surgery (BS). However, few studies have evaluated influential factors and to date there are no studies investigating individual ultraviolet B (UVB) radiation levels in BS patients. This study aimed to evaluate vitamin D deficiency and its associated factors, including UVB radiation, in Roux-Y gastric bypass (RYGB) patients. Methods This study included 104 adults (90.4% female) at least 5 years after RYGB. Patients underwent surgery in private hospitals (Private; n = 47) or in two public hospitals, one with ongoing outpatient care (Active; n = 17), and the other with discontinued service for BS (Discontinued; n = 40). 25-hydroxyvitamin D (25(OH)D) concentrations were analyzed by chemiluminescence, individual UVB radiation levels by dosimeter badges. Vitamin D intake, anthropometric, skin phototype, sociodemographic and lifestyle patterns were also assessed. Results Mean age was 49.6 ± 9.1 years and post-operative period 8.7 ± 2.2 years. The prevalence of 25(OH)D deficiency and insufficiency was 25.0% and 51.9% respectively. 25(OH)D concentration differed among the hospitals (private = 26.2 ± 8.5; active = 28.7 ± 11.4; discontinued = 23.5 ± 6.5 ng/mL; p = 0.038). A total of 26.2% of the variance observed in 25(OH)D concentrations was explained by daily UVB radiation levels (β = 0.224; p = 0.032) and vitamin D intake (β = 0.431; p 

The optimisation of skeletal health during the life cycle is critical, especially if we are to reduce the continuing rise in osteoporosis -1 in 2 women and 1 in 5 men over the age of 50 years will suffer an osteoporotic fracture. The foundations of adult bone health are laid down in the early years; therefore, optimisation of bone health in the young is fundamental. Although genetics play a major role, accounting for 70-75% of bone strength, other lifestyle and nutrition factors are known to be highly influential. Calcium (Ca) and vitamin D play critical roles in bone mineralisation as well as generally being key nutrients in health. All living cells require Ca to survive, with the majority (99%) of Ca being found in bones and teeth and the remainder in soft tissues and body fluids. Vitamin D is the generic term for two molecules: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). The former is derived by ultraviolet (UV) irradiation of ergosterol, which is distributed in plants and fungi. The latter is formed from the effect of UV irradiation on the skin. The principal role of vitamin D is to support the serum Ca concentration within narrow limits. Vitamin D is crucial for maximising gut absorption of calcium via vitamin D dependent Ca receptors. It is estimated that adequate vitamin D status increases Ca absorption to 30-40% of intake compared with only 10-15% absorption without adequate vitamin D. Intakes of Ca are a concern among certain groups of the population, for example a high proportion (>12%) of teenage boys and girls fail to meet the lower reference nutrient intake for Ca. For vitamin D, there are no dietary reference values for the age group 4-64 years as it is considered that UV exposure provides sufficient quantities of vitamin D, but there is now mounting evidence of widespread vitamin D insufficiency in the population. Weight-bearing physical activity is beneficial to the skeleton but clarification is needed of the exact type, intensity and duration required for optimal bone mass. The role of othermicronutrients on bone metabolism remains to be fully quantified. This review investigates the current evidence of the impact of dietary and lifestyle factors on bone health, with specific reference to children and adolescents and with a focus on vitamin D, Ca and weight-bearing exercise. © 2007 The Authors; Journal compilation © 2007 British Nutrition Foundation.

The study discusses the possible role of adequate vitamin D status in plasma or serum for preventing acute respiratory infections during the Covid-19 pandemic. Our arguments respond to an article, published in Italy, that describes the high prevalence of hypovitaminosis D in older Italian women and raises the possible preventive and therapeutic role of optimal vitamin D levels. Based on literature review, we highlight the findings regarding the protective role of vitamin D for infectious diseases of the respiratory system. However, randomized controlled trials are currently lacking. Adequate vitamin D status is obtained from sun exposure and foods rich in vitamin D. Studies in Brazil have shown that hypovitaminosis D is quite common in spite of high insolation. Authors recommend ecological, epidemiological and randomized controlled trials studies to verify this hypothesis.

We undertook a systematic review and meta-analysis of published papers assessing dietary protein and bone health. We found little benefit of increasing protein intake for bone health in healthy adults but no indication of any detrimental effect, at least within the protein intakes of the populations studied. This systematic review and meta-analysis analysed the relationship between dietary protein and bone health across the life-course. The PubMed database was searched for all relevant human studies from the 1st January 1976 to 22nd January 2016, including all bone outcomes except calcium metabolism. The searches identified 127 papers for inclusion, including 74 correlational studies, 23 fracture or osteoporosis risk studies and 30 supplementation trials. Protein intake accounted for 0–4% of areal BMC and areal BMD variance in adults and 0–14% of areal BMC variance in children and adolescents. However, when confounder adjusted (5 studies) adult lumbar spine and femoral neck BMD associations were not statistically significant. There was no association between protein intake and relative risk (RR) of osteoporotic fractures for total (RR(random) = 0.94; 0.72 to 1.23, I2 = 32%), animal (RR (random) = 0.98; 0.76 to 1.27, I2 = 46%) or vegetable protein (RR (fixed) = 0.97 (0.89 to 1.09, I2 = 15%). In total protein supplementation studies, pooled effect sizes were not statistically significant for LSBMD (total n = 255, MD(fixed) = 0.04 g/cm2 (0.00 to 0.08, P = 0.07), I2 = 0%) or FNBMD (total n = 435, MD(random) = 0.01 g/cm2 (−0.03 to 0.05, P = 0.59), I2 = 68%). There appears to be little benefit of increasing protein intake for bone health in healthy adults but there is also clearly no indication of any detrimental effect, at least within the protein intakes of the populations studied (around 0.8–1.3 g/Kg/day). More studies are urgently required on the association between protein intake and bone health in children and adolescents.

Context and purpose Individual participant data-level meta-regression (IPD) analysis is superior to meta-regression based on aggregate data in determining Dietary Reference Values (DRV) for vitamin D. Using data from randomized controlled trials (RCTs) with vitamin D3-fortified foods, we undertook an IPD analysis of the response of winter serum 25-hydroxyvitamin (25(OH)D) to total vitamin D intake among children and adults and derived DRV for vitamin D. Methods IPD analysis using data from 1429 participants (ages 2–89 years) in 11 RCTs with vitamin D-fortified foods identified via a systematic review and predefined eligibility criteria. Outcome measures were vitamin D DRV estimates across a range of serum 25(OH)D thresholds using unadjusted and adjusted models. Results Our IPD-derived estimates of vitamin D intakes required to maintain 97.5% of winter 25(OH)D concentrations ≥ 25 and ≥ 30 nmol/L are 6 and 12 µg/day, respectively (unadjusted model). The intake estimates to maintain 90%, 95% and 97.5% of concentrations ≥ 50 nmol/L are 33.4, 57.5 and 92.3 µg/day, respectively (unadjusted) and 17.0, 28.1 and 43.6 µg/day, respectively (adjusted for mean values for baseline serum 25(OH)D, age and BMI). Conclusions IPD-derived vitamin D intakes required to maintain 90%, 95% and 97.5% of winter 25(OH)D concentrations ≥ 50 nmol/L are much higher than those derived from standard meta-regression based on aggregate data, due to the inability of the latter to capture between person-variability. Our IPD provides further evidence that using food-based approaches to achieve an intake of 12 µg/day could prevent vitamin D deficiency (i.e., serum 25(OH)D 

Published studies have suggested a high prevalence of 25-hydroxyvitamin D (25OHD) deficiency in western dwelling South Asians, particularly in women. However, sample sizes have been relatively small with few men. Moreover, South Asians are vastly under-represented in national dietary surveys and further research into 25(OH)D status is needed. The UK Biobank is a cohort of 500,000 individuals; n 6433 are of South Asian ethnicity and have baseline serum 25(OH)D data (2006–2010, aged 40–69 years). Blood draws were spread across the year. Of note, the 25(OH)D measurements were produced using the DiaSorin Liaison XL assay which underestimates 25(OH)D by 4% at 25nmol/L, but overestimates 25(OH)D by 5–10% at ≥ 40nmol/\L(1). We used the commonly used cut-points of < 25nmol/L (deficiency), < 50nmol/L (insufficiency). In women (n 2927), median (IQR) was 24.3 (20.5) nmol/L with 50.4% < 25nmol/L, and 88.6% < 50nmol/L. In men (n 3506), median (IQR) was 21.7 (16.2) with 58.4% < 25 nmol/L and 93.8% < 50 nmol/L. Of concern, 17.8% of women and 21.1% of men had 25(OH)D < 15nmol/L. A Mann Whitney test showed that gender differences were statistically significant (P < 0.0001). In terms of ethnic sub-groups, in the Bangladeshi group (n 207), median (IQR) was 26.1 (14.3) nmol/L with 43.5% < 25nmol/L and 91.3% < 50nmol/L. In the Indian group (n 4792), median (IQR) was 23.8 (19.3) with 52.0% < 25nmol/L and 90.4% < 50nmol/L. Finally, in the Pakistani group (n 1434) median (IQR) was 19.3(14.5) with 65.7% < 25nmol/L and 94.9% < 50nmol/L. A Kruskal Wallis test showed that ethnic subgroup differences were statistically significant (P < 0.0001). To the authors’ knowledge, this is the largest analysis to date of 25(OH)D status in European dwelling South Asians. Deficiency of 25(OH)D was almost universal, with 50% or more not even reaching 25nmol/L. Of great concern, 20% of participants had levels < 15nmol/L which, although not a widely used cut-off point, still represents severe deficiency and likely osteomalacia. Moreover, these results are most probably an underestimation of this societal challenge as the UK Biobank is likely to contain participants that are healthier and more educated than the general population. In conclusion, our analyses suggest the need for urgent public health interventions to prevent and treat vitamin D deficiency in UK South Asians. This research was conducted using the UK Biobank Resource under application number 15168.

Vitamin D deficiency is a global health issue(Reference Wilson, Tripkovic and Hart1). However, little is known about the vitamin D status of the United Kingdom (UK) African-Caribbean (AC) population, even though this population group is likely at increased risk of vitamin D deficiency, due to latitude and skin type(Reference Wilson, Tripkovic and Hart1,Reference Clemens, Adams and Henderson2) . This cross-sectional study explored the 25(OH)D concentration and vitamin D intake of AC individuals from the UK Biobank Cohort, who were aged 40 years and over at baseline (2006–2010). For context, the AC population was also compared to the African (AF), South Asian (SA) and White European (WE) subsets of the UK Biobank. For AC, n = 4046 had a valid 25(OH)D measurement. Of these, n = 1499 (37.0%) were deficient (50nmol/L). Median (IQR) for 25(OH)D was 30.0 (20.9) nmol/L and median vitamin D intake was 1.6 (2.6) μg/day, with only n = 64 (4.8%) of AC meeting the UK recommended nutrient vitamin D intake of 10μg/day. For the other ethnic groups, the median (IQR) for 25(OH)D concentration was 30.2 (20.0) nmol/L in AF, 20.7 (18.5) nmol/L in SA and 49.2 (29.5) nmol/L in WE. Logistic regression showed that brown/black skin type (OR 1.77, 95% CI 1.19,2.63), winter blood draw (OR 1.22, 95% CI 0.98, 1.51), not consuming oily fish (OR 1.74, 95% CI 1.19, 2.54) and not using vitamin D supplements (OR 2.97, 95% CI 2.50, 3.53) were predictors of increased odds of vitamin D deficiency (

Background Group-specific component (GC) and cytochrome P450 Family 2 Subfamily R Member 1 (CYP2R1) genes are one of the vital genes involved in the vitamin D (vitD) metabolic pathway. Association of genetic polymorphisms in these two genes with 25-hyroxyvitamin D (25(OH)D) level has been reported in several studies. However, this association has been reported to be discrepant among populations from different ethnicities. Therefore, we aimed in this study to investigate association of the two major single nucleotide polymorphisms (SNP) in GC (rs4588 and rs7014) and a SNP (rs12794714) in CYP2R1 in postmenopausal women in Saudi Arabia. Methods This study randomly selected 459 postmenopausal women (aged ≥ 50 years) of multiple ethnicities in Jeddah, Saudi Arabia. Blood samples were collected from all participating women for DNA extraction and for assessment of serum levels of total 25(OH)D, directly measured free 25(OH)D and other biochemical parameters. SNPs in selected vitD related genes (rs4588 in GC, c.1364G>T with transcript ID: NM_001204307.1 and rs7041 in GC, c.1353A>C with transcript ID NM_001204307.1 and rs12794714 in CYP2R1, c.177G>A with transcript ID NM_024514.4) were determined in DNA samples using Sanger DNA sequencing. Results Minor allele frequency for rs4588, rs7041 and rs12794714 were 0.25, 0.44 and 0.42 respectively. Genotypes of rs7041 showed significant difference in total 25(OH)D level but not in free 25(O)D level (P=0.023). In comparison, genotypes of rs4588 and rs12794714 did not show any significant difference neither in total nor in free 25(OH)D level. Post hoc test revealed that total 25(OH)D was lower in the rs7041 TT allele compared to the GG allele (P=0.022). Chi-square test showed that vitD status was associated with rs7041 genotypes (P=0.035). In addition, rs7041 minor alleles were found to have an association with vitD deficiency with a statistical significant odds ratio (>1) of 2.24 and 3.51 with P=0.006 and P=0.007 for TG and GG genotypes respectively. Conclusion The rs7041 SNP in GC was associated with total 25(OH)D level in postmenopausal women in Saudi Arabia, while rs4588 in GC and rs12794714 in CYP2R1 did not show association with total 25(OH)D. Further studies exploring additional variants in vitD related genes are needed to understand genetic factors underlying vitD deficiency in Saudi population.

The role of vitamin D in supporting the growth and maintenance of the skeleton is robust; with recent research also suggesting a beneficial link between vitamin D and other nonskeletal health outcomes, including immune function, cardiovascular health and cancer. Despite this, vitamin D deficiency remains a global public health issue, with a renewed focus in the UK following the publication of Public Health England’s new Dietary Vitamin D Requirements. Natural sources of vitamin D (dietary and UVB exposure) are limited, and thus mechanisms are needed to allow individuals to achieve the new dietary recommendations. Mandatory or voluntary vitamin D food fortification may be one of the mechanisms to increase dietary vitamin D intakes and subsequently improve vitamin D status. However, for the food industry and public to make informed decisions, clarity is needed as to whether vitamins D2 and D3 are equally effective at raising total 25-hydroxyvitamin D (25(OH)D) concentrations as the evidence thus far is inconsistent. This review summarises the evidence to date behind the comparative efficacy of vitamins D2 and D3 at raising 25(OH)D concentrations, and the potential role of vitamin D food fortification as a public health policy to support attainment of dietary recommendations in the UK. The comparative efficacy of vitamins D2 and D3 has been investigated in several intervention trials, with most indicating that vitamin D3 is more effective at raising 25(OH)D concentrations. However, flaws in study designs (predominantly under powering) mean there remains a need for a large, robust randomised-controlled trial to provide conclusive evidence, which the future publication of the D2–D3 Study should provide (BBSRC DRINC funded: BB/ I006192/1). This review also highlights outstanding questions and gaps in the research that need to be addressed to ensure the most efficacious and safe vitamin D food fortification practices are put in place. This further research, alongside cost, availability and ethical considerations (vitamin D3 is not suitable for vegans), will be instrumental in supporting government, decision-makers, industry and consumers in making informed choices about potential future vitamin D policy and practice.

Background: Vitamin D deficiency has been associated with non-alcoholic fatty liver disease (NAFLD). However, the role of polymorphisms determining vitamin D status remains unknown. Objectives: To determine in UK children with biopsy-proven NAFLD: (i) vitamin D status throughout a 12-month period; (ii) interactions between key vitamin D-related genetic variants (NADSYN1/DHCR7, VDR, GC, CYP2R1) and disease severity. Methods: In 103 pediatric patients with NAFLD, serum 25-hydroxyvitamin D (25OHD) levels and genotypes were determined contemporaneously to liver biopsy and examined in relation to NAFLD activity score and fibrosis stage. Results: Only 19.2% of children had adequate vitamin D status; most had mean 25OHD levels considered deficient (

Seafood intake in pregnancy has been positively associated with childhood cognitive outcomes which could potentially relate to the high vitamin-D content of oily fish. However, whether higher maternal vitamin D status [serum 25-hydroxy-vitamin D, 25(OH)D] in pregnancy is associated with a reduced risk of offspring suboptimal neurodevelopmental outcomes is unclear. A total of 7065 mother-child pairs were studied from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort who had data for both serum total 25(OH)D concentration in pregnancy and at least one measure of offspring neurodevelopment (pre-school development at 6–42 months; “Strengths and Difficulties Questionnaire” scores at 7 years; IQ at 8 years; reading ability at 9 years). After adjustment for confounders, children of vitamin-D deficient mothers (< 50.0 nmol/L) were more likely to have scores in the lowest quartile for gross motor development at 30 months (OR 1.20 95% CI 1.03, 1.40), fine motor development at 30 months (OR 1.23 95% CI 1.05, 1.44), and social development at 42 months (OR 1.20 95% CI 1.01, 1.41) than vitamin-D sufficient mothers (≥ 50.0 nmol/L). No associations were found with neurodevelopmental outcomes, including IQ, measured at older ages. However, our results suggest that deficient maternal vitamin D status in pregnancy may have adverse effects on some measures of motor and social development in children under 4 years. Prevention of vitamin D deficiency may be important for preventing suboptimal development in the first 4 years of life.

This newly revised edition contains updated versions of all of the topics that were in the first edition and has been substantially expanded with an additional 5 chapters.

Vitamin D is vital to bone health and prolonged severe deficiency can lead to rickets in children and osteomalacia/osteoporosis in adults. Vitamin D is an exceptional nutrient in that its main source is exposure of the skin to UV rays, whilst it can also be ingested through diet. This study aimed to investigate the relative contribution of vitamin D supplementation and individual sunlight exposure in raising vitamin D levels, throughout winter, in ethnically identical adult women living in opposite latitudes. Within two parallel placebo-controlled randomized controlled trials (RCT), with identical study designs, 135 Brazilian women, (England, n = 56, 51˚N; Brazil, n = 79, 16˚S), were randomized to receive daily 15 μg vitamin D3 supplements or placebo, for 12 weeks. Oral vitamin D supplementation of 15 μg daily was effective at raising 25-hydroxivitamin D [25(OH)D] concentrations over winter, regardless of latitude, and the response was dependent on baseline vitamin D status. In both latitudes, supplementation prevented the seasonal concomitant increase in plasma parathyroid hormone (PTH) levels. Additionally, the individual UV radiation level was strongly correlated with 25(OH)D concentrations. The research also showed: 1) an optimal vitamin D status for bone health around 70–80 nmol/l; 2) the required UV radiation to achieve this status was 1.5 SED; 3) the vitamin D dietary intakes required to achieve these serum levels were 4.5 μg/d at a low latitude (16˚S) and 37 μg/d at high latitude (51˚N). The strength of these results is the novel analysis that directly links human in vivo individual sunlight radiation, increased vitamin D intake and 25(OH)D status, within two parallel RCTs in opposite latitudes. This study demonstrated that a daily supplement of 15 μg vitamin D3 was an effective strategy to significantly raise vitamin D status throughout the winter months in adult females, with important implications for bone health through the simultaneous lowering of PTH, regardless of latitude. Our data gives a two-fold contribution to the vitamin D field: firstly it will help raise awareness of the risk for vitamin D deficiency in low latitude regions such as most countries in South America as well as amongst South-Americans living in higher latitudes, particularly in the UK; secondly it provides key data for setting appropriate vitamin D recommendations for Brazil (which currently follows US recommendations) as well as for similar latitudes.

We live in a world with an ever-increasing ageing population. Studying healthy ageing and reducing the socioeconomic impact of age-related diseases is a key research priority for the industrialised and developing countries, along with a better mechanistic understanding of the physiology and pathophysiology of ageing that occurs in a number of age-related musculoskeletal disorders. Arthritis and musculoskeletal disorders constitute a major cause of disability and morbidity globally and result in enormous costs for our health and social-care systems. By gaining a better understanding of healthy musculoskeletal ageing and the risk factors associated with premature ageing and senescence, we can provide better care and develop new and better-targeted therapies for common musculoskeletal disorders. This review is the outcome of a two-day multidisciplinary, international workshop sponsored by the Institute of Advanced Studies entitled “Musculoskeletal Health in the 21st Century” and held at the University of Surrey from 30th June-1st July 2015. The aim of this narrative review is to summarise current knowledge of musculoskeletal health, ageing and disease and highlight strategies for prevention and reducing the impact of common musculoskeletal diseases.

This is the first 1-year longitudinal study which assesses vitamin D deficiency in young UK-dwelling South Asian women. The findings are that vitamin D deficiency is extremely common in this group of women and that it persists all year around, representing a significant public health concern. Introduction: There is a lack of longitudinal data assessing seasonal variation in vitamin D status in young South Asian women living in northern latitudes. Studies of postmenopausal South Asian women suggest a lack of seasonal change in 25-hydroxy vitamin D [25(OH)D], although it is unclear whether this is prevalent among premenopausal South Asians. We aimed to evaluate, longitudinally, seasonal changes in 25(OH)D and prevalence of vitamin D deficiency in young UK-dwelling South Asian women as compared with Caucasians. We also aimed to establish the relative contributions of dietary vitamin D and sun exposure in explaining serum 25(OH)D. Methods: This is a 1-year prospective cohort study assessing South Asian (n = 35) and Caucasian (n = 105) premenopausal women living in Surrey, UK (51 N), aged 20-55 years. The main outcome measured was serum 25(OH)D concentration. Secondary outcomes were serum parathyroid hormone, self-reported dietary vitamin D intake and UVB exposure by personal dosimetry. Results: Serum 25(OH)D

We assessed sunlight and dietary contributions to vitamin D status in British postmenopausal women. Our true longitudinal 25-hydroxyvitamin D (25(OH)D) measurements varied seasonally, being lower in the north compared to the south and lower in Asian women. Sunlight exposure in summer and spring provided 80% total annual intake of vitamin D.

Nutritional Aspects of Bone Health provides an in-depth review of the role of diet in the development and maintenance of bone health throughout the lifecycle, and prevention of osteoporosis in later life. The book is multi-authored by the world's leading researchers in this area, who have come together to formulate the first ever textbook on nutritional aspects of bone health, and includes the current and cutting edge science underpinning the prevention of bone disease.The book is structured such that, in the first section, an overview is provided on what is meant by the terms bone health and

Research has investigated 25-hydroxyvitamin D (25(OH)D) levels in the Atopic Dermatitis (AD) population, as well as changes in AD severity after vitamin D (VitD) supplementation. We performed an up-to-date systematic review and meta-analysis of these findings. Electronic searches of MEDLINE, EMBASE and COCHRANE up to February 2018 were performed. Observational studies comparing 25(OH)D between AD patients and controls, as well as trials documenting baseline serum 25(OH)D levels and clinical severity by either SCORAD/EASI scores, were included. Of 1085 articles retrieved, sixteen were included. A meta-analysis of eleven studies of AD patients vs. healthy controls (HC) found a mean difference of -14 nmol/L (95%CI -25 to -2) for all studies and -16 nmol/L (95% CI -31 to -1) for the paediatric studies alone. A meta-analysis of three VitD supplementation trials found lower SCORAD by -11 points (95% CI -13 to -9) (p ˂0·00001). This surpasses the Minimal Clinical Important Difference for AD of 9.0 points (by 22%). There were greater improvements in trials lasting three months and the mean weighted dose of all trials was 1500-1600U/day. Overall, the AD population, especially the paediatric subset, may be at high-risk for lower serum 25(OH)D. Supplementation with around 1600IU/d results in a clinically meaningful AD severity reduction.

The purpose of this study was to assess whether there is a difference in bone resorption by degree of seasonal change in 25(OH)D and whether this varies by ethnicity. In the recent D-FINES study, (Vitamin D, Food Intake, Nutrition and Exposure to Sunlight in Southern England, 2006-2007), a subset of n=65 from the 293 participants (South Asian (n 30) and Caucasian (n 35)) had blood taken in four seasons for determination of 25(OH)D and serum c-telopeptide (sCTX). sCTX was measured using an electrochemiluminescent immunoassay (Roche cobas e411). Seasonal fluctuation of 25(OH)D was assessed by calculating differences between the winter (nadir) and summer (peak) 25(OH)D. For ease of interpretation these changes were expressed as positive values. This enabled investigation of the absolute change in 25(OH)D but not its direction. This variable was then split into quartiles within ethnicity. The dependent variables were absolute concentration of sCTX in each season as well as summer to winter change in sCTX. ANCOVA was run with absolute summer and winter 25(OH)D status, age, BMI, socioeconomic status, physical activity, and dietary calcium as covariates. In the Asian group there was no clear trend between degree of seasonal fluctuation and absolute sCTX. Indeed, only the autumn data was statistically significant (F=5.93; p= 0.01) and with no consistent pattern among the quartiles. No data were significant for change in summer to winter sCTX in Asians or Caucasians despite a trend in both ethnic groups for lower sCTX in the middle quartiles relative to the highest and lowest. Last, in Caucasians, there was a non-statistically significant (p.0.05) inverse trend between cycling of 25(OH)D and absolute serum C-telopeptide levels. These data suggest lower bone resorption in all seasons in Caucasians with increased cycling, and a reduction in sCTX between summer and winter in both ethnic groups in the middle quartile relative to the other quartiles. As the values were covariate adjusted, these findings are not likely to be due to other variables. However, it must be borne in mind that these results are only trends, which is likely due to the small numbers of subjects. Further research is required to analyse banked urine samples from the D-FINES study (n 293) which would enable us to see if these results are statistically significant with increased statistical power. The D-FINES study was funded by the UK Food Standards Agency. All views are those of the authors alone

Background: Epidemiological studies have supported inverse associations between low serum 25-hydroxyvitamin D [25(OH)D] and cardiometabolic risk markers, but few randomized trials have investigated the effect of vitamin D supplementation on these markers in adolescents. Objective: The objective of this study was to investigate the effect of winter-time cholecalciferol (vitamin D3) supplementation on cardiometabolic risk markers in white, healthy 14-18 year-old adolescents in the UK (51°N) as part of the ODIN Project. Methods: In a dose-response trial, 110 adolescents (15.9±1.4 years; 43% male; 81% normal weight) were randomly assigned to receive 0, 10 or 20 μg/day vitamin D3 for 20 weeks (October-March). Cardiometabolic risk markers including BMI-for-age z-score (BMIz), waist circumference, systolic and diastolic blood pressure, fasting plasma triglycerides, cholesterol (total, HDL, LDL and total:HDL) and glucose were measured at baseline and endpoint as secondary outcomes, together with serum 25(OH)D. Intervention effects were evaluated in linear regression models as between-group differences at endpoint, adjusted for the baseline value of the outcome variable and additionally for age, sex, Tanner stage, BMIz and baseline serum 25(OH)D. Results: Mean±SD baseline serum 25(OH)D was 49.1±12.3 nmol/L and differed between groups at endpoint with concentrations of 30.7±8.6, 56.6±12.4 and 63.9±10.6 nmol/L in the 0, 10 and 20 μg/day groups respectively (P≤0.001). Vitamin D3 supplementation had no effect on any of the cardiometabolic risk markers (all P>0.05), except for lower HDL (-0.12 mmol/L, 95% CI -0.21, 0.04, P=0.003) and total cholesterol (-0.21 mmol/L, 95% CI -0.42, 0.00, P=0.05) in the 20 compared to the 10 μg/day group, which disappeared in the fully adjusted analysis (P=0.27 and P=0.30 respectively). Conclusions: Supplementation with vitamin D3 at 10 and 20 μg/25 day, which increased serum 25(OH)D concentrations during the winter-time, had no effect on markers of cardiometabolic risk in healthy 14-18 year-old adolescents. This trial was registered at clinicaltrials.gov as NCT02150122.

BACKGROUNDTwo previous meta-analyses showed smaller differences between vitamin D3 (D3) and vitamin D2 (D2) in raising serum 25-hydroxy-vitamin D [25(OH)D] and a consistently high heterogeneity, when only including daily dosing studies. OBJECTIVETo compare more frequently dosed D2 and D3 in improving total 25(OH)D and to determine the concomitant effect of response modifiers on heterogeneity, and secondly to compare the D2-associated change in 25(OH)D2 with the D3-associated change in 25(OH)D3 (PROSPERO 2021 CRD42021272674). METHODSPubMed, EMBASE, Cochrane and the Web of Science Core collection were searched for RCTs of D2 versus D3, daily or once/twice weekly dosed. After screening for eligibility, relevant data were extracted for meta-analyses to determine the standardized mean difference (SMD) when different methods of 25(OH)D analyses were used. Otherwise, the weighted mean difference (WMD) was determined. RESULTSOverall, the results based on 20 comparative studies showed D3 to be superior to D2 in raising total 25(OH)D concentrations, but D2 and D3 had a similar positive impact on their corresponding 25(OH)D hydroxylated forms. The WMD in change in total 25(OH)D based on twelve, all daily dosed D2-D3 comparisons, analyzed using LCMS/MS, was 10.39 nmol/l (40%) lower for the D2 group compared to D3 group (95% CI -14.62, -6.16; I2=64%; p25kg/m2 (p=0.99). However, information on BMI was only available in 13/17 daily dosed comparisons. CONCLUSIONSD3 leads to a greater increase of 25(OH)D than D2, even if limited to daily dose studies, but D2 and D3 had similar positive impacts on their corresponding 25(OH)D hydroxylated forms. BMI should be considered when comparing the effect of daily vitamin D2 and vitamin D3 supplementation on total 25(OH)D concentration. STATEMENT OF SIGNIFICANCEPrevious meta-analyses suggest that vitamin D3 may be more potent in increasing serum 25(OH)D concentrations than vitamin D2. In addition, it appeared that with daily dosing this difference is smaller compared to other doses, e.g. monthly/bolus. Our meta-analysis confirms this when comparing the commonly recommended more frequent dosing regimens, daily versus weekly, although residual heterogeneity remained high. BMI and baseline 25(OH)D concentration may contribute to this residual variability and may therefore be considered when recommending a daily intervention with vitamin D2 or D3.

Osteoporosis is an ageing disorder characterised by poor micro -structural architecture of the bone and an increase in the risk of fragility fractures, which often leads to hospitalisation and even-tually a loss of mobility and independence. By 2050, it is estimated that more than 30 million people in Europe will be affected by bone diseases, and European hospitalisation alone can approxi-mately cost up to 3.5 billion euros each year [1]. Although inherited variation in bone mineral density (BMD) is pre-determined by up to 85% [2], there is a window of opportunity to optimise BMD and reduce fracture risk through key modifiable lifestyle factors during the life course. An optimal diet rich in micronutrients, such as calcium, vitamin D, and potassium, has long been considered an important modifiable component of bone health, which is attributed to their direct roles within bone metabolism. Recently, there has been emerging evidence to sug-gest that protein and even an adequate intake of fruit and vege-tables may also play an important role in improving BMD [3,4]. Maintaining a physically active lifestyle is not only protective from non-communicable diseases such as cardiovascular disease but it also has been shown to lessen the risk of fractures later in life, thereby making it an imperative modifiable factor for bone health, particularly as it also supports peak bone mass attainment during childhood/adolescence and can facilitate the maintenance of bone mass throughout adulthood [5]. Other key lifestyle factors that could be potentially modified to reduce the risk of osteoporosis or osteoporotic fractures later in life include smoking status, alcohol intake, and body composition [6]. Therefore, the principle aim of this review is to highlight the recent evidence pertaining to modifiable lifestyle factors that contribute to optimal bone health and the prevention of fragility fractures in later life.(c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4.0/).

This study aimed to establish if bone turnover shows significant seasonal variation, and if this varies by ethnicity. The D-FINES study investigated 373 Surrey Caucasian (C) and Asian (A) women every season over a 12 month period (2006-2007). A random sub-sample of premenopausal C (n 18) and postmenopausal C (n 17); premenopausal A (n 13) and postmenopausal A (n 17) with blood samples for all seasons were selected. Serum C-telopeptide (sCTX) was determined by electrochemiluminescent immunoassay (Roche Diagnostics). A mixed between-within subjects ANOVA showed there was no significant main effect of season on sCTX F(3,59.0)=1.467, p=0.233. However, there was a significant between subjects effect of group F(3,61)=3.099, p=0.033, with post hoc tests showing significant differences between the two C groups (p=0.007) and postmenopausal A and premenopausal C groups (p=0.042) but no significant differences between the other groups. Last, there was no significant interaction between season and group F(9,143.741)=0.540, p=0.843. It appears that it is menopausal status, not ethnicity which is likely the main reason for the group differences. Indeed, there was no significant difference between ethnic groups of the same menopausal status. Overall, no evidence for a seasonal variation in bone resorption was found here but there was evidence for a menopausal difference in bone resorption.

The aim of this presentation was to assess the impact of a 'vegetarian diet' on indices of skeletal integrity. Analyses of existing literature were assessed in relation to bone health for: lacto-ovo-vegetarian and vegan diets vs. omnivorous; predominantly meat diets; consumption of animal vs. vegetable protein; fruit and vegetable consumption. The key findings include: (i) no differences in bone health indices between lacto-ovo-vegetarians and omnivores; (ii) conflicting data for protein effects on bone, with high and low protein intake being detrimental to the skeleton; (iii) growing support for a beneficial effect of fruit and vegetable intake on bone, with mechanisms of action currently remaining unclarified. © 2007 Elsevier B.V. All rights reserved.

Few data exist on bone turnover in South Asian women and it is not well elucidated as to whether Western dwelling South Asian women have different bone resorption levels to that of women from European ethnic backgrounds. This study assessed bone resorption levels in UK dwelling South Asian and Caucasian women as well as evaluating whether seasonal variation in 25-hydroxyvitamin D [25(OH)D] is associated with bone resorption in either ethnic group. Data for seasonal measures of urinary N-telopeptide of collagen (uNTX) and serum 25(OH)D were analysed from n=373 women (four groups; South Asian postmenopausal n=44, South Asian premenopausal n=50, Caucasian postmenopausal n=144, Caucasian premenopausal n =135) (mean (± SD) age 48 (14) years; age range 18-79 years) who participated in the longitudinal D-FINES (Diet, Food Intake, Nutrition and Exposure to the Sun in Southern England) cohort study (2006-2007). A mixed between-within subjects ANOVA (n=192) showed a between subjects effect of the four groups (P

Tuberculosis (TB) is a chronic disease affecting humans and other mammal species. Severity of TB caused by Mycobacterium tuberculosis in humans seems to be influenced by nutritional factors like vitamin D3 intake. However, this relationship has been scarcely studied in cattle and other mammals infected with Mycobacterium bovis. The aim of this work was to assess if wildlife reservoirs of M. bovis show different levels of TB severity depending on the level of vitamin D found in serum after supplementation with vitamin D3. Forty hunted wildlife mammals were included in this study: 20 wild boar and 20 red deer. Ten wild boar and ten red deer had been supplemented with a vitamin D3-enriched food, whereas the remaining animals had received no supplementation. TB diagnosis was carried out in each animal based on microbiological isolation of M. bovis. Animals infected with M. bovis were then classified as animals with localized or generalized TB depending on the location and dissemination of the lesions. Furthermore, serum levels of vitamin D2 and D3 were determined in each animal to evaluate differences not only between supplemented and non-supplemented animals but also between those with localized and generalized TB. Levels of vitamin D3 found in both, supplemented wild boar and red deer, were significantly higher than those found in the non-supplemented animals. Interestingly, higher levels of vitamin D3 were observed in animals suffering localized TB when compared to animals with generalized TB suggesting that vitamin D3 concentration correlates negatively with TB severity in these wildlife reservoirs.

Background: Children in northern latitudes are at high risk of vitamin D deficiency during winter because of negligible dermal vitamin D3 production. However, to our knowledge, the dietary requirement for maintaining the nutritional adequacy of vitamin D in young children has not been investigated. Objective: We aimed to establish the distribution of vitamin D intakes required to maintain winter serum 25-hydroxyvitamin D [25(OH)D] concentrations above the proposed cutoffs (25, 30, 40, and 50 nmol/L) in white Danish children aged 4–8 y living at 55°N. Design: In a double-blind, randomized, controlled trial 119 children (mean age: 6.7 y) were assigned to 0 (placebo), 10, or 20 μg vitamin D3/d supplementation for 20 wk. We measured anthropometry, dietary vitamin D, and serum 25(OH)D with liquid chromatography–tandem mass spectrometry at baseline and endpoint. Results: The mean ± SD baseline serum 25(OH)D was 56.7 ± 12.3 nmol/L (range: 28.7–101.4 nmol/L). Serum 25(OH)D increased by a mean ± SE of 4.9 ± 1.3 and 17.7 ± 1.8 nmol/L in the groups receiving 10 and 20 μg vitamin D3/d, respectively, and decreased by 24.1 ± 1.2 nmol/L in the placebo group (P < 0.001). A nonlinear model of serum 25(OH)D as a function of total vitamin D intake (diet and supplements) was fit to the data. The estimated vitamin D intakes required to maintain winter serum 25(OH)D >30 (avoiding deficiency) and >50 nmol/L (ensuring adequacy) in 97.5% of participants were 8.3 and 19.5 μg/d, respectively, and 4.4 μg/d was required to maintain serum 25(OH)D >40 nmol/L in 50% of participants. Conclusions: Vitamin D intakes between 8 and 20 μg/d are required by white 4- to 8-y-olds during winter in northern latitudes to maintain serum 25(OH)D >30–50 nmol/L depending on chosen serum 25(OH)D threshold. This trial was registered at clinicaltrials.gov as NCT02145195.

Now in its third edition, the best-selling Introduction to Human Nutrition continues to foster an integrated, broad knowledge of the discipline and presents the fundamental principles of nutrition science in an accessible way. With up-to-date coverage of a range of topics from food composition and dietary reference standards to phytochemicals and contemporary challenges of global food safety, this comprehensive text encourages students to think critically about the many factors and influences of human nutrition and health outcomes. Offers a global, multidisciplinary perspective on food and nutrition Covers nutrition and metabolism of proteins, lipids, carbohydrates and vitamins and minerals Explores new developments in functional foods, supplements and food fortification, and future challenges for nutrition research and practice Explains the digestion, absorption, circulatory transport, and cellular uptake of nutrients Demonstrates the structure and characteristics of nutrients, and the relationship with disease prevention A primary text in nutritional science classes worldwide, Introduction to Human Nutrition is a vital resource for students in areas of nutrition, dietetics, and related subjects that involve principles of nutrition science.

This analysis assessed whether seasonal change in 25-hydroxyvitamin D concentration was associated with bone resorption, as evidenced by serum parathyroid hormone and C-terminal telopeptide concentrations. The main finding was that increased seasonal fluctuation in 25-hydroxyvitamin D was associated with increased levels of parathyroid hormone and C-terminal telopeptide. Introduction: It is established that adequate 25-hydroxyvitamin D (25(OH)D, vitamin D) concentration is required for healthy bone mineralisation. It is unknown whether seasonal fluctuations in 25(OH)D also impact on bone health. If large seasonal fluctuations in 25(OH)D were associated with increased bone resorption, this would suggest a detriment to bone health. Therefore, this analysis assessed whether there is an association between seasonal variation in 25(OH)D and bone resorption. Methods: The participants were (n = 279) Caucasian and (n = 88) South Asian women (mean (±SD); age 48.2 years (14.4)) who participated in the longitudinal Diet, Food Intake, Nutrition and Exposure to the Sun in Southern England study (2006-2007). The main outcomes were serum 25(OH)D, serum parathyroid hormone (sPTH) and serum C-terminal telopeptide of collagen (sCTX), sampled once per season for each participant. Results: Non-linear mixed modelling showed the (amplitude/mesor) ratio for seasonal change in log 25(OH)D to be predictive of log sPTH (estimate = 0.057, 95 % CI (0.051, 0.063), p < 0.0001). Therefore, individuals with a higher seasonal change in log 25(OH)D, adjusted for overall log 25(OH)D concentration, showed increased levels of log sPTH. There was a corresponding significant ability to predict the range of seasonal change in log 25(OH)D through the level of sCTX. Here, the corresponding parameter statistics were estimate = 0.528, 95 % CI (0.418, 0.638) and p ≤ 0.0001. Conclusions: These findings suggest a possible detriment to bone health via increased levels of sPTH and sCTX in individuals with a larger seasonal change in 25(OH)D concentration. Further larger cohort studies are required to further investigate these preliminary findings. © 2013 International Osteoporosis Foundation and National Osteoporosis Foundation.

Supporting the adoption of a healthy lifestyle is essential to reduce the impact of non-communicable diseases and improve public health. The PROTEIN project(Reference Wilson-Barnes, Gymnopoulos and Dimitropoulos1), through advances in computer technology, aimed to create a novel personalised mobile application (app) and support system for healthy living and eating. This study assesses the effectiveness and perceived usefulness of advice provided by the PROTEIN app to facilitate lifestyle changes within two population groups. Eighty participants were recruited from the UK general public into two sub-groups: i) adults with excess weight (OW, n 40; BMI: 25–30 kg/m2) and ii) adults with poor-quality diets (PQD, n 40; Hb < 120g/L or adults with low fruit/ vegetable intake, defined as < 3 portions / d). Participants attended the University to provide baseline anthropometric, physical activity and general health data (or self- reported during a virtual appointment). App registration was completed using anthropometric data alongside dietary preferences and dietary ‘goals’. Participants were asked to log in to the app and follow the individualised 7-day nutrition and activity plans (NAP) recommended, and to interact with the system, via the meal logging and meal rating systems to ‘train’ the reasoning-based decision support system (RDSS) within the PROTEIN framework (1,2). After 4 weeks of use, participants were asked to report their current weight and complete two online evaluation questionnaires for system usability and behaviour change. A favourable ethical opinion was received from the Health Research Authority (ID: 294871). Data were checked for normality and are presented as mean (± SD); significance was set at p < 0.05.

The Ehlers-Danlos Syndromes (EDS) are disorders of the connective tissue. EDS presents clinical manifestations potentially related to hypovitaminosis D, such as skeletal and bone health issues (musculoskeletal pain, osteopenia, osteoporosis, osteoarthritis) (Reference Tinkle, Castori and Berglund1), whilst other characteristics of this syndrome can hinder vitamin D intake, such as gastrointestinal issues, dysphagia and disordered eating (Reference Baeza-Velasco, Lorente and Tasa-Vinyals2). Concomitantly, pain and dysautonomia may promote indoor living (Reference Kalisch, Hamonet and Bourdon3) and reduce exposure to UVB irradiation, which could affect vitamin D status. This study aimed to identify whether females with EDS are more likely to have lower serum 25- hydroxyvitamin D (25(OH)D). This was a cross-sectional study, analysing data from 224 EDS cases and 224 controls, using UK Biobank baseline data. The UK Biobank cohort includes over 500 K individuals, aged 40–69 years at baseline (data collection 2006–2010). The UK Biobank study was conducted according to the Declaration of Helsinki and all procedures were approved by the UK North West Multi-Centre Research Ethics Committee (MREC); application 11/NW/0382. Written informed consent was obtained from all subjects.

Vitamin D is a unique nutrient. Firstly, it acts as a pro-hormone and secondly, the requirement for vitamin D can be met by both endogenous synthesis from sunlight and by dietary sources. This complicates the determination of dietary requirements for vitamin D, which along with the definition of optimal vitamin D status, have been highly controversial and much debated over recent years. Adolescents are a population group at high risk of low vitamin D status, which is concerning given the important role of vitamin D, and calcium, in promoting normal bone mineralisation and attainment of peak bone mass during this rapid growth phase. Dietary vitamin D recommendations are important from a public health perspective in helping to avoid deficiency and optimise vitamin D status for health. However limited experimental data from winter-based dose-response randomised trials in adolescents has hindered the development of evidence-based dietary requirements for vitamin D in this population group. This review will highlight how specifically designed randomised trials and the approach adopted for estimating such requirements can lead to improved recommendations. Such data indicates that vitamin D intakes of between 10 and ~30 µg/day may be required to avoid deficiency and ensure adequacy in adolescents, considerably greater than the current recommendations of 10-15 µg/day. Finally this review will consider the implications of this on public health policy, in terms of future refinements of vitamin D requirement recommendations and prioritisation of public health strategies to help prevent vitamin D deficiency

African Caribbean (AC) populations are ‘at risk’ of vitamin D deficiency in the UK (1). Vitamin D dietary intake is especially important in winter months, when cutaneous production of vitamin D from UVB rays is not possible in Northern latitudes. (1). Vitamin D together with calcium play a crucial role in bone health (1). The aim of this study was to assess the dietary intake of vitamin D and calcium of the AC population and the association with bone health outcomes. A cross-sectional study was carried out at the University of Surrey, UK, in winter 2020. Healthy, self-identified AC women aged >18 years, not in menopause or taking vitamin D containing supplements, were recruited. Dietary intakes were assessed using 4-day estimated food diaries, analysed via Nutritics software (v5.099), whilst Dual Energy X-ray Absorptiometry scans of the whole body and left hip were used to assess bone health and analysed using Hologic QDR (Hologic Inc., S/N 200071, USA). Anthropometric measurements and blood samples were taken and UVB exposure was assessed. The relationships between vitamin D and calcium intakes and bone heath (bone mineral density and bone mineral composition) were analysed by Pearson correlation. Statistical analysis was performed using SPSS (IBM, v27).

The aim of the present study was to assess the seasonal relationship between serum 25(OH)D concentration, lean mass and muscle strength. This was a secondary data analysis of a subgroup of 102 postmenopausal women participating in the 2006–2007 D-FINES (Vitamin D, Food Intake, Nutrition and Exposure to Sunlight in Southern England) study. The cohort was assessed as two age subgroups:

There is a lack of research into 25-hydroxyvitamin D (25(OH)D) status, light exposure and sleep patterns in South Asian populations. In addition, results of research studies are conflicting as to whether there is an association between 25(OH)D status and sleep quality. We investigated 25(OH)D status, self-reported and actigraphic sleep quality in n = 35 UK dwelling postmenopausal women (n = 13 South Asians, n = 22 Caucasians), who kept daily sleep diaries and wore wrist-worn actiwatch (AWL-L) devices for 14 days. A subset of n = 27 women (n = 11 South Asian and n = 16 Caucasian) also wore a neck-worn AWL-L device to measure their light exposure. For 25(OH)D concentration, South Asians had a median ± IQR of 43.8 ± 28.2 nmol/L, which was significantly lower than Caucasians (68.7 ± 37.4 nmol/L)(P = 0.001). Similarly, there was a higher sleep fragmentation in the South Asians (mean ± SD 36.9 ± 8.9) compared with the Caucasians (24.7 ± 7.1)(P = 0.002). Non-parametric circadian rhythm analysis of rest/activity patterns showed a higher night-time activity (L5) (22.6 ± 14.0 vs. 10.5 ± 4.4; P = 0.0008) and lower relative amplitude (0.85 ± 0.07 vs. 0.94 ± 0.02; P ˂ 0.0001) in the South Asian compared with the Caucasian women. More South Asians (50%) met the criteria for sleep disorders (PSQI score ˃5) than did Caucasians (27%) (P = 0.001, Fishers Exact Test). However, there was no association between 25(OH)D concentration and any sleep parameter measured (P ˃ 0.05) in either ethnic group. South Asians spent significantly less time in illuminance levels over 200 lx (P = 0.009) than did Caucasians. Overall, our results show that postmenopausal South Asian women have lower 25(OH)D concentration than Caucasian women. They also have higher sleep fragmentation, as well as a lower light exposure across the day. This may have detrimental implications for their general health and further research into sleep quality and light exposure in the South Asian ethnic group is warranted.

The UK Biobank is a cohort study that collects data on diet, lifestyle, biomarkers, and health to examine diet-disease associations. Based on the UK Biobank, we reviewed 36 studies on diet and three health conditions: type 2 diabetes (T2DM), cardiovascular disease (CVD), and cancer. Most studies used one-time dietary data instead of repeated 24 h recalls, which may lead to measurement errors and bias in estimating diet-disease associations. We also found that most studies focused on single food groups or macronutrients, while few studies adopted a dietary pattern approach. Several studies consistently showed that eating more red and processed meat led to a higher risk of lung and colorectal cancer. The results suggest that high adherence to "healthy" dietary patterns (consuming various food types, with at least three servings/day of whole grain, fruits, and vegetables, and meat and processed meat less than twice a week) slightly lowers the risk of T2DM, CVD, and colorectal cancer. Future research should use multi-omics data and machine learning models to account for the complexity and interactions of dietary components and their effects on disease risk.

Vitamin D is essential for bone development during adolescence and low vitamin D status during this critical period of growth may impact bone mineralization, potentially reducing peak bone mass and consequently increasing the risk of osteoporosis in adulthood. Therefore, the high prevalence of vitamin D inadequacy and deficiency in adolescent populations is of great concern. However, there is currently a lack of consensus on the 25-hydroxyvitamin D [25(OH)D] concentration, the widely accepted biomarker of vitamin D status, that defines adequacy, and the vitamin D intake requirements to maintain various 25(OH)D thresholds are not well established. While the current intake recommendations of 10–15 μg/day may be sufficient to prevent vitamin D deficiency (25(OH)D < 25–30 nmol/l), greater intakes may be needed to achieve the higher threshold levels proposed to represent adequacy (25(OH)D > 50 nmol/l). This review will address these concerns and consider if the current dietary recommendations for vitamin D in adolescents are sufficient.

Now widely adopted on courses throughout the world, the prestigious Nutrition Society Textbook series provides students with the scientific basics in nutrition in the context of a systems and disease approach rather than on a nutrient by nutrient basis. In addition books provide a means to enable teachers and students to explore the core principles of nutrition and to apply these throughout their training to foster critical thinking at all times. This NS Textbook on Sport and Exercise Nutrition has been written to cover the latest information on the science and practice of sport and exercise nutrition. A key concept behind this textbook is that it aims to combine the viewpoints of world leading nutrition experts from both academia/research and a practical stand point. Plus where necessary there are additional practitioner based authors to ensure theory is translated into practice for each chapter in the form of either 'practice tips' or 'information sheets' at the end of relevant chapters. The textbook in essence can be divided into three distinct but integrated parts: Part 1: covers the key components of the science that supports the practice of sport and exercise nutrition including comprehensive reviews on: nutrients both in general and as exercise fuels; exercise physiology; hydration, micronutrients; and supplements. Part 2: moves into focusing on specific nutrition strategies to support different types of training including: resistance; power/sprint; middle distance/speed endurance; endurance; technical/skill, team; and specific competition nutrition needs. The unique format of this textbook is that it breaks down nutrition support into training specific as opposed to the traditional sport specific support. This reflects the majority of current sport and exercise requirements of the need to undertake concurrent training and therefore facilitating targeted nutrition support to the different training components through the various macro and micro training cycles. Part 3: explores some of the practical issues encountered in working in the sport and exercise nutrition field and includes key sport related topics such as: disability sport; weight management; eating disorders; bone and gut health; immunity; injury; travel; and special populations and situations. READERSHIP: Students of nutrition and dietetics at both undergraduate and postgraduate level. All those working in the field of nutrition and related health sciences. © 2011 The Nutrition Society.

Vitamin D is unlike any other nutrient, with the majority of the vitamin derived from sunlight rather than food(Reference Chen, Chimeh and Lu1,Reference Jones2) . There is a lack of research looking into the vitamin D status of the African-Caribbean population worldwide. This population may be at high risk of vitamin D deficiency because of their darkly pigmented skin that hinders ability to synthesise vitamin D cutaneously, especially in those living at higher latitudes(Reference Chen, Chimeh and Lu1). The aim of this study was to investigate the vitamin D status (as measured by 25(OH)D and dietary intake) of the African-Caribbean population globally.

Little published data has assessed the association between socio-economic deprivation and 25- hydroxyvitamin D (25(OH)D) concentration. One study found low socio-economic status predicted vitamin D deficiency(Reference Leger-Guist'hau, Domingues-Faria and Miolanne1), but another did not(Reference Ersoy, Kizilay and Yilmaz2). Our objective was to assess the relationship between 25(OH)D and Townsend Deprivation Index (TDI) in a large sample, using data from the UK Biobank Cohort, which has data on 502,000 individuals (baseline 2006–2010, aged 40 years or over). Blood draws, for measurement of serum 25(OH)D by the DiaSorin Liaison XL assay, were spread across the year with each participant sampled once. The UK Biobank holds ethical approval from UK North West Multi-Centre Research Ethics Committee (11/NW/0382).

Background Vitamin D deficiency has been documented to be prevalent, even in low latitude regions; and this may be related to sun exposure behaviors. The aim of the current study was to assess the association between serum 25-hydroxyvitamin D [25(OH)D] concentrations and lifestyle–related factors in a sample of Brazilian women living at latitude 21º 8′ S. Methods A cross-sectional study was undertaken in 101 women aged 35 years or older in July 2019 to assess the association between 25(OH)D concentration and level of exposure to ultraviolet radiation (UVR), smoking habits, alcohol consumption, and physical activity levels. Age, body mass index (BMI), and postmenopausal status were investigated. Findings According to the slope coefficient for individual daily UVR levels, the concentration of 25(OH)D increased by 5 nmol / L for each extra Standard Erythema Dose of UVR, regardless of age and BMI (p < 0·001). Postmenopausal women had a significantly higher mean concentration of 25(OH)D (p = 0·01), higher UVR exposure (p = 0·01) and lower BMI (p = 0·005) compared with younger women, independent of other confounders including smoking, alcohol, occupation and physical activity. Interpretation Although postmenopausal women from Brazil had higher mean concentrations of 25(OH)D than younger women, more studies are necessary to understand how sun exposure and lifestyle variables interfere with these levels. These findings have important public health implications since they suggest that vitamin D deficiency in older age is not inevitable. Funding This study was funded by an award received by Universities Global Partnership Network – UGPN. KVSS and SLO receive scholarship from CAPES, Brazilian Ministry of Education. HR receives a productivity grant from CNPq.

Almost one in five adults aged 19–65 years in the UK has a low serum vitamin D concentration (below 25 nmol/l) according to the National Diet and Nutrition Survey (NDNS) (Roberts et al. 2018), which puts them at increased risk of the manifestations of vitamin D deficiency, described below. In some age groups, prevalence is even higher; for example, 39% among adolescent girls aged 11–18 years. Government recommendations in the UK emphasise the importance of ensuring adequate vitamin D for everyone to protect bone and muscle health. Public Health England (PHE) advises that adults and children over the age of 5 years require an average of 10 µg of vitamin D a day and should consider taking a daily supplement during autumn and winter (a combination of diet and sunshine exposure is sufficient for most people during the spring and summer provided they spend time outside). There is also specific advice for the under-fives (Table 1). People who have a higher risk of vitamin D deficiency are being advised to take a supplement all year round (Table 1).

Objectives: The aim of this study was to evaluate bone health and the potential influencing factors of bone metabolism disorders in adults >5 y after Roux-en-Y gastric bypass (RYGB) surgery.Methods: In this cross-sectional study, patients who were >= 5 y post-RYGB were invited. Bone health consid-ered as bone mineral content (BMC) and bone mineral density (BMD) in this study was assessed by dual x-ray absorptiometry. We also assessed 25-hydroxy-vitamin D concentrations, individual ultraviolet B radia-tion levels, serum ionized calcium, alkaline phosphatase, parathyroid, anthropometric, and body composition.Results: The study evaluated 104 adults (90% women; 49.6 +/- 9.1 y old; postoperative period 8.7 +/- 2.2 y). Lumbar and femoral BMC and BMD were positively correlated to body mass index (BMI), appendicular lean mass (ALM), and negatively to %excess of weight loss (EWL). Femoral BMD was negatively correlated to age, and both femoral BMD and BMC were positively correlated to weekly exposed body part score. Sex, age, BMI, ALM, and weekly exposed body part score explained 35% and 54% of the total variance of femoral BMD and BMC, respectively.Conclusions: The present findings suggested that older age, lower BMI, higher %EWL, lower ALM, and lower weekly body part exposure score are important determinants in lowering BMD and BMC parameters in long-term post-bariatric surgery individuals, rather than serum 25-hydroxy-vitamin D and parathyroid.(c) 2022 Elsevier Inc. All rights reserved.

The year 2022 will feature in history books for a number of reasons; but in the world of nutrition, it marks the Centenary of the landmark investigation by Dame Harriette Chick and her co-workers. Exactly 100 years ago, working with malnourished children in a clinic in Vienna shortly after the First World War, they showed that rickets in children in Austria could be prevented or cured by cod liver oil supplementation. This cod liver oil was subsequently recognised as a particularly rich source of vitamin D (Chick et al., 1922). A century later, vitamin D continues to be a specific hot topic as evidenced by the number of papers published in recent years in Nutrition Bulletin (Allen et al., 2014; Buttriss & Lanham-New, 2020; Clark et al., 2021; Gibson-Moore, 2021; Guo et al., 2019; Hengist et al., 2019; Lanham-New et al., 2022; Mendes et al., 2018; Smith & Hart, 2017; Spiro & Buttriss, 2014; Tripkovic, 2013; Tripkovic et al., 2017; Wilson-Barnes et al., 2020). These papers have been brought together in a specially curated Virtual Issue [https://onlinelibrary.wiley.com/doi/toc/10.1111/(ISSN)1467-3010.Vitamin-D-Centenary]. Dame Harriette Chick was awarded the British Nutrition Foundation (BNF) Prize in 1974 for her contribution to nutrition research. By then already a Centenarian, she chose her ground-breaking research on vitamin D as the theme for her BNF Annual Lecture (Chick, 1976), in which she summarised her work in Vienna, Austria in 1919–1922, presenting the chemical, clinical and sociological aspects of her story. Dame Harriette worked at the Lister Institute of Preventative Medicine, London, United Kingdom from 1905 to 1970, and she and colleagues were sent to Vienna by the Accessory Food Factor Committee of the Medical Research Council to investigate whether the diseases affecting the population were the result of vitamin deficiencies (Figure 1).

Stress fractures are common amongst healthy military recruits and athletes. Reduced vitamin D availability, measured by serum 25-hydroxyvitamin D (25OHD) status, has been associated with stress fracture risk during the 32-week Royal Marines (RM) training programme. A gene-environment interaction study was undertaken to explore this relationship to inform specific injury risk mitigation strategies. Fifty-one males who developed a stress fracture during RM training (n = 9 in weeks 1-15; n = 42 in weeks 16-32) and 141 uninjured controls were genotyped for the vitamin D receptor (VDR) FokI polymorphism. Serum 25OHD was measured at the start, middle and end (weeks 1, 15 and 32) of training. Serum 25OHD concentration increased in controls between weeks 1-15 (61.8 +/- 29.1 to 72.6 +/- 28.8 nmol/L, p = 0.01). Recruits who fractured did not show this rise and had lower week-15 25OHD concentration (p = 0.01). Higher week-15 25OHD concentration was associated with reduced stress fracture risk (adjusted OR 0.55[0.32-0.96] per 1SD increase, p = 0.04): the greater the increase in 25OHD, the greater the protective effect (p = 0.01). The f-allele was over-represented in fracture cases compared with controls (p

Introduction Sarcopenia is a progressive loss in muscle mass, strength and function, the adverse consequences of which are severe, affecting quality of life and placing an increasing burden on social and healthcare systems. Vitamin D status is known to be associated with markers of sarcopenia, namely muscle mass, strength and function. Also, resistance exercise training (RET) is currently the only proven intervention to treat sarcopenia. However, very little data exist on the influence of combining the two interventions of vitamin D supplementation and resistance exercise training, although a recent systematic review provides tentative support for the current study’s hypothesis that the combined intervention may further improve musculoskeletal function above exercise training alone. The aim of the present study is to determine whether vitamin D3 supplementation is any more effective in improving musculoskeletal function when combined with RET compared with exercise training alone in older adults. Methods and analysis This double-blinded randomised placebo-controlled trial will recruit a target of 127 eligible men and women aged ≥65 years living independently or in sheltered housing within the Birmingham area to two groups: (1) 6 months RET and placebo or (2) 6 months RET and 800 IU/d vitamin D3. Measures of muscle power (Nottingham Power Rig), body composition (dual energy X-ray absorptiometry), muscle function (short physical performance battery, timed up and go), falls and fractures as events will be assessed. Assessments will take place at baseline and postintervention, with intermittent monitoring of bone turnover, calcium and vitamin D. The primary outcome will be lower limb extensor power output. Analyses of within-group changes and between-group differences in outcome measures are planned. Ethics and dissemination The EXVITD study has ethical approval granted by the Black Country National Health Service Research Ethics Committee (14/WM/1220). Results of this trial will be submitted for publication in peer-reviewed journals and presented at conferences. The study is being conducted according to the principles of the Declaration of Helsinki.

[...]this is of great research interest and public health concern as vitamin D deficiency has been shown to have key implications for long-term health outcomes in humans(2). Most (78%) used vitamin D supplements to manage vitamin D deficiency, commonly D3 (57%), meeting clinical recommendations. The findings identify urgent need for HCP nutrition education to help attenuate vitamin D deficiency prevalence.

Vitamin D is best known for its role in maintaining bone health and calcium homeostasis. However, it also exerts a broad range of extra-skeletal effects on cellular physiology and on the immune system. Vitamins D and D share a high degree of structural similarity. Functional equivalence in their vitamin D-dependent effects on human physiology is usually assumed but has in fact not been well defined experimentally. In this study we seek to redress the gap in knowledge by undertaking an in-depth examination of changes in the human blood transcriptome following supplementation with physiological doses of vitamin D and D . Our work extends a previously published randomized placebo-controlled trial that recruited healthy white European and South Asian women who were given 15 µg of vitamin D or D daily over 12 weeks in wintertime in the UK (Nov-Mar) by additionally determining changes in the blood transcriptome over the intervention period using microarrays. An integrated comparison of the results defines both the effect of vitamin D or D on gene expression, and any influence of ethnic background. An important aspect of this analysis was the focus on the changes in expression from baseline to the 12-week endpoint of treatment each individual, harnessing the longitudinal design of the study. Whilst overlap in the repertoire of differentially expressed genes was present in the D or D -dependent effects identified, most changes were specific to either one vitamin or the other. The data also pointed to the possibility of ethnic differences in the responses. Notably, following vitamin D supplementation, the majority of changes in gene expression reflected a down-regulation in the activity of genes, many encoding pathways of the innate and adaptive immune systems, potentially shifting the immune system to a more tolerogenic status. Surprisingly, gene expression associated with type I and type II interferon activity, critical to the innate response to bacterial and viral infections, differed following supplementation with either vitamin D or vitamin D , with only vitamin D having a stimulatory effect. This study suggests that further investigation of the respective physiological roles of vitamin D and vitamin D is warranted.

Few data exist on the effect of dietary and lifestyle factors on indices of bone health in women living in Middle Eastern countries. As part of our on-going bone health study in 212 Saudi Arabian women, a total of 100 premenopausal and 112 postmenopausal women living in the city of Jeddah were studied. They were aged 20-30 years and 45-60 years, respectively. Measurements were made on weight and height as well as spine, hip and calcaneal bone mass. All subjects were interviewed concerning their habitual dietary intake, physical activity levels and general lifestyle. Prevalence of osteopenia and osteoporosis was common amongst postmenopausal women. Vitamin D deficiency was extensive in both the pre- and postmenopausal women Saudi women. Further analysis of the dataset are required to examine extensively the effect of diet on bone health in Middle Eastern women, but these data are a cause for concern regarding the extent of vitamin D deficiency. © 2007 Elsevier B.V. All rights reserved.

By 2050, it is predicted that one in four people in the United Kingdom will be aged 65 years and over. Increases in lifespan are not always translated into years spent in good health. Incidence rates for chronic diseases are increasing, with treatments allowing people to live longer with their disease. There is good evidence to support changes to lifestyle to maintain or improve body composition, cognitive health, musculoskeletal health, immune function and vascular health in older adults. Much research has been done in this area, which has produced significant support for foods and nutrients that contribute to improved healthspan. Yet two major barriers remain: firstly, older adult consumers are not meeting current UK recommendations for macro‐ and micronutrients that could benefit health and quality of life and secondly, the UK‐specific recommendations may not be sufficient to support the ageing population, particularly for nutrients with key physiological roles. More work is needed to improve intakes of specific foods, diets and nutrients by older adults, through a variety of mechanisms including (i) development of specific food products; (ii) improved clarity of information and (iii) appropriate marketing, and policy changes to enable incentives. The Food4Years Ageing Network aims to build a wide‐reaching and multidisciplinary community that is committed to the development, integration and communication of healthy, affordable foods and specific diets for all older adults across the UK food landscape. The Network will identify evidence‐based strategies for improving food intake and nutrition in older adults, paving the way to “living well while living longer.”

The principal objectives of the D-FINES study are to compare vitamin D status, food intake, bone health indices and sunlight exposure in Caucasian and Asian women living in Southern England. It is known that in women both muscle and fat mass influence whole-body BMD(1) and the aim of the present subsidiary study was to examine for differences in body composition and compare the relationship between body composition components in Asian and Caucasian women. Measurements of body composition were undertaken in seventy-two Asian and 227 Caucasian women in autumn–winter (A/W) with a follow-up assessment in spring–summer (S/S) by dual X-ray absorptiometry (QDR-4500; Hologic Inc., Bedford, MA, USA). Measures of whole-body bone mineral density (BMD), whole-body bone mineral content (BMC), fat mass and lean mass were undertaken. Regional as well as total measurements were available.

Vitamin D (vitD) deficiency has been suspected as a risk factor for type 2 diabetes mellitus (T2DM). It has been reported that an inverse relationship exists between vitD status and risk of T2DM. The aim of this study was to investigate whether there is an association between vitD status and glycemic profile and other metabolic parameters among postmenopausal women with T2DM (living in Saudi Arabia). A cross-sectional study was conducted at King Fahad Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia. One thirty six (n = 136) postmenopausal females (age ≥ 50 years) living in Jeddah city, Saudi Arabia, with T2DM were randomly recruited in this study. Anthropometric measures, blood pressure readings and fasting blood samples were obtained fro all study participants. Several biochemical parameters were estimated in fasting serum samples including total 25(OH)D, HbA1c, insulin, glucose, c-peptide and lipid profile. Surrogate markers for insulin resistance were calculated using Homeostasis Model Assessment for insulin resistance and beta cell activity (HOMA-IR, HOMA-β), Quantitative insulin sensitivity check index (QUICK-I) and McAuley's index. VitD deficiency was defined as serum total 25(OH)D level below 20 ng/ml.The Mean (± SD) serum levels of total 25(OH)D were 13.8 ± 8.6 ng/ml with 79% of the study cohort being vitD deficient. Furthermore, serum total 25(OH)D levels were found to be inversely correlated with fasting insulin (r = -0.24, p = 0.029), HOMA-IR (r = -0.24, p = 0.03), and positively correlated with McAuley's index (r = 0.22, p = 0.048) and QUICK-I (r = 0.25, p = 0.024). In conclusion, vitD deficiency is highly prevalent among postmenopausal women with T2DM living in Jeddah, Saudi Arabia. VitD was found to be associated with insulin resistance. Whether vitD supplements are able to improve insulin sensitivity and other parameters in T2DM postmenopausal women should be further investigated.

Vitamin D concentrations are a function of sunlight exposure and dietary intake. However, current dietary vitamin D recommendations do not consider differences in country-specific sunlight availability or spontaneous individual exposure. We aimed to investigate the effects of vitamin D supplementation and sunlight exposure on vitamin D concentrations in Brazilian women living in high compared with low latitudes. In 2 parallel, double-blind, randomized placebo-controlled trials, Brazilian women living in England (51°N) composed "without ultraviolet B (UVB) exposure" groups and those living in Brazil (16°S) composed the "with UVB exposure" groups (mean age, 31.39 ± 8.7 years). Participants received 15 μg cholecalciferol or placebo daily for 12 weeks during wintertime. Serum 25-hydroxyvitamin D [25(OH)D] concentrations, the primary outcome, were assessed by HPLC-MS/MS, vitamin D intakes were assessed by 4-day diet diaries, and sunlight exposure was assessed by UVB dosimeters. The effects of supplementation and UVB exposure were tested by the intention to treat with a linear mixed model. The 25(OH)D concentrations increased in both supplemented groups [from 75.1 ± 22.0 to 84.8 ± 21.0 nmol/L (P = 0.004) in the group with UVB exposure; from 38.1 ± 15.9 to 55.1 ± 12.2 nmol/L (P 

There is still limited data on the association between 25-hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), and bone health in healthy younger adults, particularly in Latin America. This cross-sectional analysis aimed to investigate the associations of 25(OH)D and plasma PTH concentrations with bone parameters, and potential confounders, in women living in a high (England) or low (Brazil) latitude country. Bone was assessed by either peripheral quantitative computed tomography (pQCT) (England) or dual-energy x-ray absorptiometry (DXA) scan (Brazil), serum 25(OH)D concentrations by high performance liquid chromatography tandem mass spectrometry (HPLC-MS) and PTH by the chemiluminescent method. In participants living in England, total volumetric bone mineral density (vBMD) was significantly higher in women

Following the work of Avenell et al. [1, 2] that has raised concerns about the integrity of the Yamaguchi Osteoporosis Prevention Study (YOPS) conducted by Ishida and Kawai, [3] we would like to issue an adjustment to our systematic review on the effectiveness of vitamin K on bone mineral density and fractures [4]. The work of Ishida and Kawai that has been questioned was included in our systematic review and was considered to be at high risk of bias. The study was included in four meta-analyses within our results. We feel there is a need for rapid correction when concerns, such as this one, are identified [5]. We do not think the removal of the YOPS study changes the overall results of our paper or the conclusions we drew regarding fractures or bone mineral density. We have provided recalculated estimates for each of these meta-analyses without the YOPS study. Total Clinical Fractures - Figure 2. This meta-analysis was performed with a subgroup analysis based on the risk of bias assessment. As the study by Ishida and Kawai was deemed to be at high risk of bias, the results of the low risk of bias studies remain unchanged. Removal of the YOPS study changes the overall odds ratio (OR) from 0.72 (95%CI 0.55 to 0.95) to 0.74 (95%CI 0.56 to 0.97). Total Vertebral Fractures - Figure 3. This meta-analysis was performed with a subgroup analysis based on the risk of bias assessment. As the YOPS study was deemed to be at high risk of bias, the results of the low risk of bias studies remain unchanged. Removal of the Ishida and Kawai study changes the overall odds ratio from 0.96 (95%CI 0.83 to 1.11) to 0.98 (95%CI 0.85 to 1.14). This also does not change the conclusions or interpretation of our review. Mean difference in Bone mineral Density of the Radius at 12 Months - Figure 4, part 3. The YOPS study had a weighting of 37.49% in this meta-analysis and thus the removal of this study did change the estimate of the effect for this analysis. The estimate changed from 0.14 (95%CI − 1.04 to 1.33) to − 0.58 (95%CI − 1.24 to 0.08). This means that the result now favours the control arm over vitamin K. Mean difference in Bone Mineral Density of the Radius at 24 months - Figure 5, part 3 Only two studies had data available for this, YOPS and Cheung et al. Taking the results only from Cheung et al. [6], the estimate would be 0.00 (95%CI − 0.85 to 0.85).

Background: There are conflicting views in the literature as to whether vitamin D2 and vitamin D3 are equally effective in increasing and maintaining serum concentrations of 25-hydroxyvitamin D [25(OH)D], particularly at lower doses of vitamin D. Objective: We aimed to investigate whether vitamin D2 or vitamin D3 fortified in juice or food, at a relatively low dose of 15 μg/d, was effective in increasing serum total 25(OH)D and to compare their respective efficacy in South Asian and white European women over the winter months within the setting of a large randomized controlled trial. Design: A randomized, double-blind, placebo-controlled food-fortification trial was conducted in healthy South Asian and white European women aged 20–64 y (n = 335; Surrey, United Kingdom) who consumed placebo, juice supplemented with 15 μg vitamin D2, biscuit supplemented with 15 μg vitamin D2, juice supplemented with 15 μg vitamin D3, or biscuit supplemented with 15 μg vitamin D3 daily for 12 wk. Serum 25(OH)D was measured by liquid chromatography–tandem mass spectrometry at baseline and at weeks 6 and 12 of the study. Results: Postintervention in the 2 ethnic groups combined, both the vitamin D3 biscuit and the vitamin D3 juice groups showed a significantly greater absolute incremental change (Δ) in total 25(OH)D when compared with the vitamin D2 biscuit group [Δ (95% CI): 15.3 nmol/L (7.4, 23.3 nmol/L) (P < 0.0003) and 16.0 nmol/L (8.0, 23.9 nmol/L) ( P < 0.0001)], the vitamin D2 juice group [Δ (95% CI): 16.3 nmol/L (8.4, 24.2 nmol/L) (P < 0.0001) and 16.9 nmol/L (9.0, 24.8 nmol/L) (P < 0.0001)], and the placebo group [Δ (95% CI): 42.3 nmol/L (34.4, 50.2 nmol/L) (P < 0.0001) and 42.9 nmol/L (35.0, 50.8 nmol/L) (P < 0.0002)]. Conclusions: With the use of a daily dose of vitamin D relevant to public health recommendations (15 μg) and in vehicles relevant to food-fortification strategies, vitamin D3 was more effective than vitamin D2 in increasing serum 25(OH)D in the wintertime. Vitamin D3 may therefore be a preferential form to optimize vitamin D status within the general population. This trial was registered at www.controlled-trials.com as ISRCTN23421591.

Aim: This study aimed to assess whether seasonal cycling of 25(OH)D (25-dihydroxy vitamin D) is associated with bone health. Method: A subgroup of 65 South Asian and Caucasian women who took part in the 2006-2007 D-FINES study was analysed. During this study they had blood drawn in four seasons for determination of 25(OH)D and serum c-telopeptide (sCTX)and in autumn and spring they had a DEXA scan (Hologic). Cycling of 25(OH)D was assessed by calculating the difference between the winter (nadir) and summer (peak) 25(OH)D and for ease of interpretation, expressing all change as positive values. Dependent variables analysed were absolute values for autumn femoral neck and lumbar spine BMD, BMC and bone area, and absolute sCTX in each season. Also, change in sCTX from summer to winter and change in the DEXA bone indices from autumn to spring were analysed. Results: ANCOVA, controlling for summer and winter 25(OH)D status, age, BMI, socioeconomic status, physical activity, and dietary calcium showed no statistically significant association (p>0.05) between quartile of cycling of 25(OH)D and any bone measurement in either ethnic group except in the Asians for absolute autumn CTX (F=5.925, p=0.01, fig 1) and change in FNBMC (F=3.111, p=0.05, see fig.3). Also, in Asians only, absolute autumn lumbar spine BMD approached significance (F =2.780, p=0.07, see fig 2). Conclusions: It has been suggested that some findings of increased risk of some cancers in countries with high 25(OH)D could be due to slow adaption of CYP27B1 and CYP24 to fluctuating 25(OH)D (1). This begs the question as to whether seasonal cycling of 25(OH)D could be detrimental to bone. Indeed, a recent review discussed a correlation between 25(OH)D and bone indices (2). The lack of an association between cycling and most bone indices found here does not support this view that 25(OH)D cycling is detrimental to bone. However, in Asians only, the loss of femoral neck BMC during the year in the top and bottom quartiles but gain in the 3rd quartile, and the increased autumn sCTX in the third quartile warrants further investigation.

Background Adolescents are a population group at high risk of low vitamin D status, yet the evidence base for establishing dietary vitamin D requirements to ensure adequacy remains weak. Objective To establish the distribution of vitamin D intakes required to maintain serum 25- hydroxyvitamin D [25(OH)D] concentrations above proposed cut-offs (25, 30, 40 and 50 nmol/L) during the winter-time in white males and females (14-18 years) in the UK (51o 9 N). Design In a dose-response trial, 110 adolescents (age 15.9 ± 1.4 years; 43% male) were randomizedto receive daily 0, 10 or 20 µg vitamin D3 supplements for 20 weeks during the winter-time. A non-linear regression model was fit to the total vitamin D intake (diet plus supplemental) and post-intervention serum 25(OH)D concentrations, and regression predicted values were used to estimate the vitamin D intakes required to maintain serum 25(OH)D concentrations above specific cut-offs. Results Mean (± SD) serum 25(OH)D concentrations increased from 49.2 ± 12.0 to 56.6 ± 12.4 nmol/L and from 51.7 ± 13.4 to 63.9 ± 10.6 nmol/L in the 10 and 20 µg/day groups respectively, and decreased in the placebo group from 46.8 ± 11.4 to 30.7 ± 8.6 nmol/L (all p ≤ 0.001). Vitamin D intakes required to maintain post-intervention 25(OH)D concentrations > 25 and > 30 nmol/L in 97.5% of adolescents were estimated as 10.1 and 13.1 µg/day respectively, and 6.6 µg/day to maintain 50% of adolescents > 40 nmol/L. As the response of 25(OH)D plateaued at 46 nmol/L, there is uncertainty in estimating the vitamin D intake required to maintain 25(OH)D > 50 nmol/L in 97.5% of adolescents, but it did exceed 30 µg/day Conclusions Vitamin D intakes of between 10 and ~30 µg/day are required by white adolescents during the winter-time in order to maintain serum 25(OH)D concentrations > 25 – 50 nmol/L, depending on the serum 25(OH)D threshold chosen.

Previous research suggests vitamin K may increase bone mass, prevent loss of bone mineral density (BMD), and possibly reduce fracture incidence. The purpose of this study was to update the systematic review and meta-analysis of the effect of both vitamin K1 and vitamin K2 (menaquinone-4 and menaquinone-7) on bone turnover, BMD and fracture risk that we published in 2007 in the light of key vitamin K supplementation studies completed in the last 30 months. The Cochrane Library (1994-2009) and EMBASE (1980-2009) databases were searched for relevant cross sectional, longitudinal and intervention studies. Thirty three studies were included in the systematic review and seven in the meta-analysis. Results from the systematic review for vitamin K1 suggested a significant negative correlation with undercarboxylated osteocalcin (ucOC), but mixed results for total OC, bone resorption markers and fracture, and no association with BMD. The meta analysis supported these results, showing a significant effect of vitamin K1 supplementation on reducing ucOC (p,0.00001, Z=15.59, weighted mean difference=-21.23 95% CI (-23.90 to-18.57)), but no significant effect on BMD at any site (P=0.78, Z=0.28, weighted mean difference=0.00, 95%CI (0.00 to 0.01)). There was insufficient data to analyse fracture incidence, bone resorption or OC in the K1 metaanalysis. Results from the systematic review of K2 studies showed a significant negative association of K2 on ucOC in intervention studies. The intervention studies, but not cross-sectional studies, independently associated vitamin K2 with fracture risk. No effect of vitamin K2 supplementation on bone resorption was found for any study type, but the intervention studies were associated with increased BMD. This was supported by results from the vitamin K2 meta-analysis for a reduction in ucOC (p,0.00001, Z=8.75, weighted mean difference=95% CI (-68.54 to-43.45)) and increased BMD from combined sites (p=0.004, Z=3.86, weighted mean difference= 95% CI (1.24-6.48)). These findings suggest vitamin K; especially K2, may be beneficial for bone health, as ucOC is an independent risk factor for osteoporotic fracture. In this analysis, K2, but not K1 supplementation, was associated with increased BMD. However, overall the results from the studies were too conflicting to recommend routine supplementation. Further, higher quality and more homogenous studies are needed before any clear conclusions can be made about vitamin K and bone health.

The effects of urban living on health are becoming increasingly important, due to an increasing global population residing in urban areas. Concomitantly, due to immigration, there is a growing number of ethnic minority individuals (African, Asian or Middle Eastern descent) living in westernised Higher Latitude Countries (HLC) (e.g. Europe, Canada, New Zealand). Of concern is the fact that there is already a clear vitamin D deficiency epidemic in HLC, a problem which is likely to grow as the ethnic minority population in these countries increases. This is because 25-hydroxyvitamin D (25(OH)D) status of ethnic groups is significantly lower compared to native populations. Environmental factors contribute to a high prevalence of vitamin D deficiency in HLC, particularly during the winter months when there is no sunlight of appropriate wavelength for vitamin D synthesis via the skin. Also, climatic factors such as cloud cover may reduce vitamin D status even in the summer. This may be further worsened by factors related to urban living, including air pollution, which reduces UVB exposure to the skin, and less occupational sun exposure (may vary by individual HLC). Tall building height may reduce sun exposure by making areas more shaded. In addition, there are ethnicity-specific factors which further worsen vitamin D status in HLC urban dwellers, such as low dietary intake of vitamin D from foods, lower production of vitamin D in the skin due to increased melanin and reduced skin exposure to UVB due to cultural dress style and sun avoidance. A multidisciplinary approach applying knowledge from engineering, skin photobiology, nutrition, town planning and social science is required to prevent vitamin D deficiency in urban areas. Such an approach could include reduction of air pollution, modification of sun exposure advice to emphasise spending time each day in non-shaded urban areas (e.g. parks, away from tall buildings), and advice to ethnic minority groups to increase sun exposure, take vitamin D supplements and/or increase consumption of vitamin D rich foods in a way that is safe and culturally acceptable. This review hopes to stimulate further research to assess the impact of high latitude, urban environment and ethnicity on the risk of vitamin D deficiency.

Few data exist looking at vitamin D status and bone health in school-aged boys and girls from Saudi Arabia. The present study aimed to determine the extent of poor vitamin D status in school boys and girls aged 6-18 years and to examine if there was any difference in status with age, physical activity and veiling and concomitant effects on bone.

The Rank Forum on Vitamin D was held on 2nd and 3rd July 2009 at the University of Surrey, Guildford, UK. The workshop consisted of a series of scene-setting presentations to address the current issues and challenges concerning vitamin D and health, and included an open discussion focusing on the identification of the concentrations of serum 25-hydroxyvitamin D (25(OH)D) (a marker of vitamin D status) that may be regarded as optimal, and the implications this process may have in the setting of future dietary reference values for vitamin D in the UK. The Forum was in agreement with the fact that it is desirable for all of the population to have a serum 25(OH)D concentration above 25 nmol/l, but it discussed some uncertainty about the strength of evidence for the need to aim for substantially higher concentrations (25(OH)D concentrations>75 nmol/l). Any discussion of ‘optimal’ concentration of serum 25(OH)D needs to define ‘optimal’ with care since it is important to consider the normal distribution of requirements and the vitamin D needs for a wide range of outcomes. Current UK reference values concentrate on the requirements of particular subgroups of the population; this differs from the approaches used in other European countries where a wider range of age groups tend to be covered. With the re-emergence of rickets and the public health burden of low vitamin D status being already apparent, there is a need for urgent action from policy makers and risk managers. The Forum highlighted concerns regarding the failure of implementation of existing strategies in the UK for achieving current vitamin D recommendations.

There is some evidence that South Asian women may have an increased risk of osteoporosis compared with Caucasian women, although whether South Asians are at increased risk of fracture is not clear. It is unknown whether older South Asian women differ from Caucasian women in bone geometry. This is the first study, to the authors' knowledge, to use peripheral Quantitative Computed Tomography (pQCT) to measure radial and tibial bone geometry in postmenopausal South Asian women. In comparison to Caucasian women, Asian women had smaller bone size at the 4% (-18% p

Abstract Background and Objective There has been a resurgence of interest in the controversial relationship between dietary protein and bone health. This paper reports the first systematic review and meta-analysis of the relationship between protein and bone health in healthy human adults. Data sources/Methods The MEDLINE® (January 1966 to September 2007) and EMBASE (1974- July 2008) databases were electronically searched for all relevant studies of healthy adults, excluding studies examining calcium excretion or calcium balance. Results In cross sectional surveys, all pooled r values for the relationship between protein intake and BMD/BMC at the main clinically relevant sites were significant and positive, with protein intake explaining 1-2% of BMD. A meta-analysis of randomised, placebo controlled trials indicated a significant positive influence of all protein supplementation on lumbar spine BMD, but showed no association with relative risk (RR) of hip fractures. No significant effects were identified for soy protein or milk basic protein (MBP) on lumbar spine BMD. Conclusion A small positive effect of protein supplementation on lumbar spine BMD in randomised placebo controlled trials supports the positive association between protein intake and bone health found in cross sectional surveys. However, these results were not supported by cohort study findings for hip fracture risk. Any effects found were very small and had 95% confidence intervals which were close to zero. Therefore there is a small benefit of protein on bone health found here but any benefit may not necessarily translate into reduced fracture risk in the long term.

Introduction Musculoskeletal injuries are common during military and other occupational physical training programs. Employers have a duty of care to reduce employees’ injury risk, where females tend to be at greater risk than males. However, quantification of principle co-factors influencing the sex–injury association, and their relative importance, remain poorly defined. Injury risk co-factors were investigated during Royal Air Force (RAF) recruit training to inform the strategic prioritization of mitigation strategies. Material and Methods A cohort of 1,193 (males n = 990 (83%); females n = 203 (17%)) recruits, undertaking Phase-1 military training, were prospectively monitored for injury occurrence. The primary independent variable was sex, and potential confounders (fitness, smoking, anthropometric measures, education attainment) were assessed pre-training. Generalized linear models were used to assess associations between sex and injury. Results In total, 31% of recruits (28% males; 49% females) presented at least one injury during training. Females had a two-fold greater unadjusted risk of injury during training than males (RR = 1.77; 95% CI 1.49–2.10). After anthropometric, lifestyle and education measures were included in the model, the excess risk decreased by 34%, but the associations continued to be statistically significant. In contrast, when aerobic fitness was adjusted, an inverse association was identified; the injury risk was 40% lower in females compared with males (RR = 0.59; 95% CI: 0.42–0.83). Conclusions Physical fitness was the most important confounder with respect to differences in males’ and females’ injury risk, rather than sex alone. Mitigation to reduce this risk should, therefore, focus upon physical training, complemented by healthy lifestyle interventions.

More data is urgently required examining the link between poor vitamin D status on bone health and muscle function in different UK ethnic groups. The D-FINES study examined a total of 373 Surrey-dwelling Caucasian (C) and Asian (A) women in four seasons of the year for diet, sunlight exposure, 25-hydroxyvitamin D (25(OH)D) and grip strength (GS). In the autumn season, lumbar spine bone mineral density (LSBMD) was also measured. The specific aim of this work was to examine differences in LSBMD and GS in A and C pre and postmenopausal women according to 25(OH)D. When women were grouped by 25(OH)D (

The vitamin D status of the United Kingdom (UK) African-Caribbean (AC) population remains under-researched, despite an increased risk of vitamin D deficiency due to darker skin phenotypes and living at a high latitude. This cross-sectional study explored the vitamin D status and intake of AC individuals (n = 4046 with a valid serum 25(OH)D measurement) from the UK Biobank Cohort, aged ≥40 years at baseline (2006–2010). Over one third of the population were deficient (50 nmol/L). Median (IQR) 25(OH)D was 30.0 (20.9) nmol/L. Logistic regression showed that brown/black skin phenotype, winter blood draw, not consuming oily fish and not using vitamin D supplements predicted increased odds of vitamin D deficiency, whilst older age and a summer or autumn blood draw were significantly associated with reduced odds of vitamin D deficiency. Vitamin D deficiency and insufficiency were prevalent in this AC population and is of considerable concern given the individual and societal implications of increased morbidity. Public health messaging for this group should focus on year-round vitamin D supplementation and increasing intakes of culturally appropriate vitamin D-rich foods. These data also support the urgent requirement for a revised vitamin D RNI for ethnic groups.

Background: Measurement of free 25-hydroyvitamin D [25(OH)D] status has been suggested as a more representative marker of vitamin D status than that of total 25(OH) D. Previously, free 25(OH)D could only be calculated indirectly; however, a newly developed direct assay for the measurement of free 25(OH)D is now available. The aim of this study therefore was to investigate directly measured total and free vitamin D levels association with metabolic health in postmenopausal healthy women living in Saudi Arabia. Methods: A sample of 302 postmenopausal women aged ≥ 50 years (n=302) living in Saudi Arabia were recruited in a cross-section study design. Blood samples were collected from subjects for measurement of serum levels of total 25(OH)D, directly measured free 25(OH)D, metabolic bone parameters, lipid profile, and other biochemical tests. Results: A positive correlation was found between directly measured free and total 25(OH)D (r=0.64, P

Objective: Vitamin D deficiency (serum 25-hydroxyvitamin D˂25nmol/L) is extremely common in western-dwelling South Asians but evidence regarding vitamin D supplement usage in this group is very limited. This work identifies demographic, dietary and lifestyle predictors associated with vitamin D supplement use. Design: Cross-sectional analysis of baseline vitamin D supplement use data. Setting: UK Biobank cohort. Subjects: In total, n 8024 South Asians (Bangladeshi, Indian, Pakistani), aged 40-69 years. Results: Twenty-three % of men and 39% of women (P˂0.001) [22% of Bangladeshis, 32% of Indians, 25% of Pakistanis (P˂0.001)] took a vitamin D containing supplement. Median vitamin D intakes from diet were low at 1.0-3.0 micrograms per day, being highest in Bangladeshis and lowest in Indians (P˂0.001). Logistic regression modelling showed that females had a higher odds of vitamin D supplement use than males (odds ratio (OR) = 2.02; 95% confidence interval (CI) 1.79 to 2.28). A lower supplement usage was seen in younger persons (40-60 years) (OR=0.75; 95% CI 0.65 to 0.86 reference= ˃60 years), and those living outside of Greater London (OR=0.53 to 0.77), with borderline trends for a lower body mass index, higher oily fish intake and higher household income associated with increased odds of vitamin D supplement use. Conclusions: Vitamin D supplements were not used by most South Asians and intakes from diet alone are likely to be insufficient to maintain adequate vitamin D status. Public health strategies are now urgently required to promote the use of vitamin D supplements in these specific UK South Asian sub-groups.

Vitamin D can be synthesized in the skin via sunlight exposure as well as ingested through diet. Vitamin D deficiency is currently a major global public health issue, with increasing prevalence in both low and high latitude locations. This cross-sectional analysis aimed to compare the intensity of individual Ultraviolet B radiation levels between women of the same ethnicity living in England and Brazil, respectively; and to investigate the association with circulating 25(OH)D concentrations. We analysed data from 135 Brazilian women (England, n = 56, 51 degrees N; Brazil, n = 79, 16 degrees S) recruited for the D-SOL study (Interaction between Vitamin D Supplementation and Sunlight Exposure in Women Living in Opposite Latitudes). Serum 25(OH)D concentrations were analysed by high performance liquid chromatography tandem mass spectrometry (HPLC-MS), individual UVB radiation via UVB dosimeter badges and dietary intake via 4-day diet diaries. Anthropometric, skin phototype, sociodemographic and lifestyle patterns were also assessed. Mean serum 25(OH)D concentration of England residents was significantly lower than Brazil residents. Daily individual UVB radiation level showed a strong significant positive correlation with serum 25(OH)D concentrations. The required UVB radiation to achieve 75 nmol/L was 2.2 SED and 38.8% of the total variance in 25(OH)D concentrations was explained uniquely by daily individual UVB radiation, after controlling for the influence of age and body mass index. Thus, these results highlight the strong positive association between serum 25(OH)D concentrations and individual UVB radiation and the influence of different individual characteristics and behaviours. Collectively, these factors contribute to meaningful, country-specific, public health strategies and policies for the efficient prevention and treatment of vitamin D inadequacy.

Aim: Bone turnover is a well studied phenomenon, however it is still unclear as to whether bone shows a season driven rhythm over the course of the year, particularly in ethnic groups. Some studies have found a significant seasonal variation in bone resorption markers but others have not. This study aimed to establish if bone turnover shows significant seasonal variation as this has practical implications in terms of the use of bone markers in diagnostics. Method: The D-FINES study (Vitamin D, Food Intake, Nutrition and Exposure to Sunlight in Southern England) investigated 373 Surrey Caucasian (C) and Asian (A) women every season over a 12 month period (2006-2007). A random sub-sample of premenopausal C (n 18) and postmenopausal C (n 17); premenopausal A (n 13) and postmenopausal A (n 17) with blood samples for all seasons were selected. Serum C-telopeptide (sCTX) was determined by electrochemiluminescent immunoassay on a cobas e411 automated analyser (Roche Diagnostics). Results: As shown in the Figure above, a mixed between-within subjects ANOVA showed there was no significant main effect of season F(3,59.0)=1.467, p=0.233. However, there was a significant between subjects effect of group F(3,61)=3.099, p=0.033, with post hoc tests showing significant differences between the two C groups (p=0.007) and between the postmenopausal A and premenopausal C groups (p=0.042) but no significant differences between the other groups. Last, there was no significant interaction between season and group F(9,143.741)=0.540, p=0.843. The lower sCTX in the younger premenopausal groups is as would be expected. However, unexpectedly, there was a non-significant trend in the postmenopausal groups for the A women to have a lower mean sCTX than the C women. In contrast, in the premenopausal women, the sCTX was lower in the C group. Therefore it appears that it is menopausal status, not ethnicity which is likely the main reason for the group differences. Indeed, there was no significant difference between ethnic groups of the same menopausal status. Conclusions: Overall, no evidence for a seasonal variation in bone resorption was found here but there was evidence for a menopausal difference in bone resorption. However, numbers of participants in this preliminary analysis was small, and the trend for an ethnic difference in the postmenopausal women might be statistically significant with higher subject numbers. Further analysis with a larger sample is planned.

The link between vitamin D and bone health is well established. However, little is known about the bone health, vitamin D status, and lifestyle characteristics of women living in Saudi Arabia. To characterize: i) bone health indices; ii) vitamin D status; iii) potential influential of sunlight exposure and physical activity level. A total of 100 premenopausal aged 20-30 years and 112 postmenopausal aged 45-60 years were included. Bone mineral density was determined at the lumbar spine and femoral neck. Serum levels of 25-hydroxyvitamin D, intact parathyroid hormone, and ionized calcium and phosphorus were measured. The subjects interviewed about their physical activity levels and lifestyle. Using the WHO criteria, 37% of the premenopausal and 52% of the postmenopausal were osteopenic at the lumbar spine. Vitamin D deficiency was highly prevalent in Saudi women, with 98% of women being below the IOM recommended level of 50nmol/L. There was a significant correlation between duration of sunlight exposure (min/day) and axial BMD and calcaneal bone mass in partly veiled women. These data indicate that younger and older Saudi Arabian women had poor bone health and that their vitamin D status and lifestyle factors do not promote skeletal integrity. © 2013. Marsland Press, Zhengzhou University.

This is the first 1-year longitudinal study which assesses vitamin D deficiency in young UK-dwelling South Asian women. The findings are that vitamin D deficiency is extremely common in this group of women and that it persists all year around, representing a significant public health concern. Introduction There is a lack of longitudinal data assessing seasonal variation in vitamin D status in young South Asian women living in northern latitudes. Studies of postmenopausal South Asian women suggest a lack of seasonal change in 25-hydroxy vitamin D [25(OH)D], although it is unclear whether this is prevalent among premenopausal South Asians. We aimed to evaluate, longitudinally, seasonal changes in 25(OH)D and prevalence of vitamin D deficiency in young UK-dwelling South Asian women as compared with Caucasians. We also aimed to establish the relative contributions of dietary vitamin D and sun exposure in explaining serum 25(OH)D. Methods This is a 1-year prospective cohort study assessing South Asian (n = 35) and Caucasian (n = 105) premenopausal women living in Surrey, UK (51° N), aged 20–55 years. The main outcome measured was serum 25(OH)D concentration. Secondary outcomes were serum parathyroid hormone, self-reported dietary vitamin D intake and UVB exposure by personal dosimetry. Results Serum 25(OH)D 

It has been hypothesised that the U shaped association between 25(OH)D and some health outcomes may be due to large seasonal fluctuations of 25(OH)D1. It is unknown whether such fluctuation of 25(OH)D (‘cycling’) influences bone health. This is an important issue, because if ‘cycling’ is detrimental for bone, then winter only rather than year round vitamin D supplementation may be useful for bone health to ‘blunt’ the rhythm. In the D-FINES study, n = 373 women (South Asian/Caucasian) had repeated measurements in four seasons for serum 25(OH)D and PTH, as well as a DXA scan in autumn and spring. Serum C-telopeptide (sCTX) was also measured in a random subset (n = 66). Cosinor regression analysis was used to identify individuals showing a significant rhythm (p < 0.10) (‘cyclers’) and those not showing a significant seasonal rhythm (‘non-cyclers’). Potential differences in bone indices between the two groups were assessed within ethnicity. Dependent variables analysed were absolute values for autumn femoral neck and lumbar spine BMD, BMC and bone area, and absolute sCTX and sPTH in each season. Also, change in sCTX and sPTH from summer to winter and change in DXA bone indices from autumn to spring were analysed. ANCOVA was run, adjusting for summer and winter 25(OH)D status, age, socioeconomic status, physical activity, and dietary calcium. BMI was also controlled for in the analysis due to its negative correlation with seasonal change in 25(OH)D. There was no statistically significant difference (p>0.05) between ‘cyclers’ and ‘non-cyclers’ for any of the bone indices in either ethnic group. However, there were trends for a higher CTX and PTH in ‘cyclers’ versus ‘non-cyclers’ in both ethnic groups in every season, but no differences for BMD or BMC (Figs. 1–4). This suggests tentatively that ‘cycling’ could be associated with changes in bone metabolism but may not translate into structural changes. In summary, there is no clear evidence here to suggest that ‘cycling’ is detrimental to bone health, although there are trends in PTH and CTX that warrant further investigation with a larger sample.

Background: Low serum 25-hydroxyvitamin D [25(OH)D] has been associated with unfavorable cardiometabolic risk profiles in many observational studies in children, but very few randomized controlled trials have investigated this. Objective: We explored the effect of winter-time cholecalciferol (vitamin D3) supplementation on cardiometabolic risk markers in young, white, 4- to 8-y-old healthy Danish children (55°N) as part of the pan-European ODIN project. Methods: In the ODIN Junior double-blind, placebo-controlled, dose-response trial, 119 children (mean ± SD age: 6.7 ± 1.5 y; 36% male; 82% normal weight) were randomly allocated to 0, 10 or 20 μg/d of vitamin D3 for 20 wk (October–March). Cardiometabolic risk markers including BMI-for-age z score (BMIz), waist circumference, systolic and diastolic blood pressure, serum triglycerides and cholesterol (total, LDL, HDL, and total:HDL), plasma glucose and insulin, and whole-blood glycated hemoglobin were measured at baseline and endpoint as secondary outcomes together with serum 25(OH)D. Intervention effects were evaluated in linear regression models as between-group differences at endpoint adjusted for baseline value of the outcome, and additionally for age, sex, baseline serum 25(OH)D, BMIz, time since breakfast, and breakfast content. Results: Mean ± SD serum 25(OH)D was 56.7 ± 12.3 nmol/L at baseline and differed between groups at endpoint with concentrations of 31.1 ± 7.5, 61.8 ± 10.6, and 75.8 ± 11.5 nmol/L in the 0-, 10-, and 20 μg/d groups, respectively (P < 0.0001). Vitamin D3 supplementation had no effect on any of the cardiometabolic risk markers in analyses adjusted for baseline value of the outcome (all P ≥ 0.05), and additional covariate adjustment did not change the results notably. Conclusions: Preventing the winter decline in serum 25(OH)D with daily vitamin D3 supplementation of 10 or 20 μg had no cardiometabolic effects in healthy 4- to 8-y-old Danish children. This trial was registered at www.clinicaltrials.gov as NCT02145195.

It is known that skin pigmentation reduces the penetration of ultraviolet radiation (UVR) and thus photosynthesis of 25-hydroxvitamin D (25(OH)D). However ethnic differences in 25(OH)D production remain to be elucidated.The aim of this study was to investigate differences in vitamin D production between UK South Asian and Caucasian postmenopausal women, in response to a defined and controlled exposure to UVR.Seventeen women; 9 white Caucasian (skin phototype II and III), 8 South Asian women (skin phototype IV and V) participated in the study, acting as their own controls. Three blood samples were taken for the measurement of vitamin D status during the run in period (9 days, no sunbed exposure) after which, all subjects underwent an identical UVR exposure protocol irrespective of skin colour (9 days, 3 sun bed sessions, 6, 8 and 8minutes respectively with approximately 80% body surface exposed). Skin tone was measured four times during the study.Despite consistently lower 25(OH)D levels in South Asian women, they were shown to synthesise vitamin D as efficiently as Caucasians when exposed to the same dose of UVR. Interestingly, the baseline level of vitamin D rather than ethnicity and skin tone influenced the amount of vitamin D synthesised.This study have found no ethnic differences in the synthesis of 25(OH)D, possibly due to the baseline differences in 25(OH)D concentration or due to the small population size used in this study. Applying mixed linear model, findings indicated no effect of ethnicity and skin tone on the production of vitamin D; baseline level and length of exposure were the critical factors. To confirm that ethnicity and skin tone has no effect on 25(OH)D production, a larger sample size study is required that considers other ethnic groups with highly pigmented skin. Initial vitamin D status influences the amount of UVB needed to reach equal serum concentrations.