Search

Objective: To evaluate the uptake of universal vitamin D supplementation during pregnancy, its effectiveness in preventing vitamin D deficiency and the factors associated with these., Design: The regional public health organisation in Ayrshire, Scotland has a policy of universal provision of vitamin D supplements (10 µg/d) to all pregnant women for the duration of their pregnancy. Pregnant women in this area were recruited at their 12-week antenatal appointment. Blood samples were collected at the 12-week and 34-week appointments. To account for the seasonal variation, women were recruited in two cohorts: summer and winter. Telephone interviews were conducted at 34 weeks to assess the uptake of vitamin D supplements during pregnancy. Other variables were obtained from medical records., Setting: The study was conducted in the NHS Ayrshire and Arran Health Board in Scotland., Participants: 612 pregnant women (aged 15-44 years) living in Ayrshire (latitude 55°), Scotland., Results: Sixty-six percentage took supplementation as recommended. Consumption of supplementation was significantly associated with a higher median serum 25-hydroxyvitamin D concentrations at 34 weeks. Despite this at 34 weeks, 33 % of the summer cohort had insufficient or deficient vitamin D status, while 15 % of the winter cohort had insufficient or deficient status. In multivariable analysis, only adherence and season were independent predictors of vitamin D status., Conclusions: While supplementation improved and maintained vitamin D status during pregnancy, it was not adequate to ensure all those insufficient at 12 weeks achieved sufficient status at the end of pregnancy.

Objective: This paper aims to report South East Asian Nutrition Surveys (SEANUTS) II Malaysia data on nutritional status, dietary intake and nutritional biomarkers of children aged 6 months to 12 years., Design: Cross-sectional survey conducted in 2019-2020., Setting: Multistage cluster sampling conducted in Central, Northern, Southern and East Coast regions of Peninsular Malaysia., Participants: 2989 children aged 0·5-12·9 years., Results: Prevalences of stunting, thinness, overweight and obesity among children aged 0·5-12·9 years were 8·9 %, 6·7 %, 9·2 % and 8·8 %, respectively. Among children below 5 years old, 11·4 % were underweight, 13·8 % had stunting and 6·2 % had wasting. Data on nutritional biomarkers showed that a small proportion of children aged 4-12 years had Fe (2·9 %) and vitamin A deficiencies (3·1 %). Prevalence of anaemia was distinctly different between children below 4 years old (40·3 %) and those aged 4 years and above (3·0 %). One-fourth of children (25·1 %) had vitamin D insufficiency, which was twice as prevalent in girls (35·2 % v . boys: 15·6 %). The majority of children did not meet the recommended dietary intake for Ca (79·4 %) and vitamin D (94·8 %)., Conclusions: Data from SEANUTS II Malaysia confirmed that triple burden of malnutrition coexist among children in Peninsular Malaysia, with higher prevalence of overnutrition than undernutrition. Anaemia is highly prevalent among children below 4 years old, while vitamin D insufficiency is more prevalent among girls. Low intakes of dietary Ca and vitamin D are also of concern. These findings provide policymakers with useful and evidence-based data to formulate strategies that address the nutritional issues of Malaysian children.

Objective: To investigate the association between serum vitamin D (25-hydroxy-cholecalciferol) (25(OH)D) concentrations and cognitive impairment in older adults living in Southern Brazil., Design: Cross-sectional analysis using data from the second follow-up wave of the populational-based EpiFloripa Aging Cohort Study was collected in 2013-2014., Setting: Cognitive impairment was evaluated using the Mini-Mental State Examination (MMSE). Blood samples were collected to measure serum vitamin D concentrations using a chemiluminescent microparticle immunoassay. Vitamin D concentrations were distributed in quartiles (Q1: 4·0-20·7 ng/ml; Q2: 20·8-26·6 ng/ml; Q3: 26·7-32·0 ng/ml and Q4: 32·1-60·1 ng/ml), and its association with cognitive impairment was tested by crude and adjusted logistic regression (sociodemographic, behavioural and health aspects) using Q4 as a reference group., Participants: 200 men and 371 women aged 60 years or older participated in this study., Results: The prevalence of probable cognitive impairment was 21·7 %. Those without cognitive impairment had a higher mean of vitamin D serum concentrations (26·8 v . 24·6, P = 0·014). In the crude analysis, only individuals in Q2 of vitamin D presented an increased risk for probable cognitive impairment compared with Q4 (highest quartile) (OR 2·65, 95 % CI 1·46, 4·81), remaining significant in the adjusted analysis (OR 6·04, 95 % CI 2·78, 13·13). While Q1 (lowest quartile) was not associated in the crude analysis, but when adjusted, an increased risk of cognitive impairment was observed., Conclusion: The lowest quartile of vitamin D was directly associated with probable cognitive impairment in older adults in Southern Brazil. More studies are needed to investigate whether maintaining adequate serum levels may represent a significant factor in preventing age-related neurological disorders as well as to verify the need for new cutoff points for this age group.

Objective: The association between 25-hydroxyvitamin D (25(OH)D) and maternal depression (MD) is deemed to be inconclusive. The current analysis aimed to quantify the relationship between 25(OH)D serum concentrations, the main indicator of vitamin D nutritional status, and MD., Design: Dose-response meta-analysis., Setting: A systematic search in PubMed, Embase and Web of Science from inception to June 2019., Participants: Relevant observational studies reporting risk estimates and 95 % CI of random effects for 25(OH)D concentration on MD were identified., Results: Twelve observational studies with thirteen independent reports involving 10 317 pregnant women were included. Compared with the lowest category of 25(OH)D, the pooled OR for the highest category of MD was 0·49 (95 % CI 0·35, 0·63); a high heterogeneity was observed (P = 0·001, I2 = 82·1 %). A non-linear association between 25(OH)D and MD was found (P for non-linearity = 0·001); the dose-response analysis indicated that the lowest pooled OR was at blood 25(OH)D concentrations of 90-110 nmol/l. Subgroup analyses suggested a stronger association between 25(OH)D and MD in summer time (OR 0·25, 95 % CI 0·08, 0·43) than in other seasons (OR 0·68, 95 % CI 0·52, 0·83) (P for interaction = 0·008). A visual inspection of funnel plot and Begg's and Egger's tests did not indicate any evidence of publication bias., Conclusions: Low circulating 25(OH)D is associated with MD, and our analysis suggests that they influence each other. Further randomised controlled trials would be needed to determine the direction of causation.

Objective: To determine the level of vitamin D and to identify the association between vitamin D and depressive symptoms in apparently healthy Korean male adults., Design: A retrospective study design. Among 43 513 participants between 1 March and 30 November 2018, after eliminating participants with a history of depression or vitamin D deficiency, 9058 were included. To determine the level of vitamin D, serum 25-hydroxyvitamin D [25(OH)D] was measured. To assess the level of depression, the Korean version of the Center for Epidemiologic Studies Depression Scale (CES-D) was used., Setting: South Korea., Participants: Male adults who underwent routine health check-ups., Results: The average vitamin D level was 22·31 ± 7·09 ng/ml as 25(OH)D, while the number of subjects in the vitamin D insufficiency group with a finding of <20 ng/ml was 3783 (41·8 %). The mean CES-D score in all subjects was 8·31 ± 5·97 points, and the proportion of the depressive symptoms group with a score of ≥16 was 8·71 %. The OR of patients in the depressive symptoms group also being in the insufficiency group was found to be 1·49 (95 % CI 1·12, 2·00)., Conclusions: A total of 41·8 % of apparently healthy male adults had vitamin D levels <20 ng/ml. We identified an association between vitamin D insufficiency and depressive symptoms in apparently healthy Korean male adults.

Objective: The aim of the study was to assess the potential association between serum 25-hydroxyvitamin D (25(OH)D) and whole-body bone mineral density (BMD) among 16-year-old adolescents and to study the prevalence of 25(OH)D insufficiency, defined as concentration under 50 nmol/l., Design: A cross-sectional study., Setting: Reykjavik, Iceland, latitude 64°08'N. Measurements took place in the Icelandic Heart Association's research lab during April-June 2015., Participants: In total, 411 students in Reykjavik, Iceland, were invited to participate, 315 accepted the invitation (76·6 %) and 289 had valid data (mainly Caucasian)., Results: 25(OH)D < 50 nmol/l was observed in 70 % of girls and 66·7 % of boys. 25(OH)D ≥ 50 nmol/l was significantly associated with higher whole-body BMD after adjusting for the influence of sex, height, fat mass and lean mass. A linear relationship between 25(OH)D and whole-body BMD was significant for 25(OH)D < 50 nmol/l (n 199, P < 0·05) but NS for 25(OH)D ≥ 50 nmol/l (n 86, P = 0·48)., Conclusions: Our results are in line with some but not all previous studies on the relationship between BMD and 25(OH)D in adolescents. The observed difference in BMD between those with above v. below a 25(OH)D concentration of 50 nmol/l was of about a fifth of one SD, which may have a clinical relevance as one SD decrease in volumetric BMD has been associated with a 89 % increase in 2 years risk of fracture. Icelandic adolescents should be encouraged to increase their vitamin D intake as it is possible that their current intake is insufficient to achieve optimal peak bone mass.

Objective: To explore the extent to which micronutrient deficiencies (MND) affect children's health-related quality of life (HRQoL), using vitamin D deficiency (VDD) as a case study., Design: Proxy valuation study to estimate the impact of VDD on the HRQoL of younger (0-4 years) and older (>4 years) children. We used the Child Health Utility 9 Dimension (CHU9D) questionnaire to estimate HRQoL for children within six VDD-related health states: 'hypocalcaemic cardiomyopathy', 'hypocalcaemic seizures', 'active rickets', 'bone deformities', 'pain and muscle weakness' and 'subclinical VDD'., Setting: Sampling was not restricted to any particular setting and worldwide experts were recruited., Participants: Respondents were paediatric bone experts recruited through network sampling., Results: Thirty-eight experts completed the survey. The health state with the largest detrimental impact (mean score (se)) on children's HRQoL was hypocalcaemic cardiomyopathy (0·47 (0·02)), followed by hypocalcaemic seizures (0·50 (0·02)) and active rickets (0·62 (0·02) in young children; 0·57 (0·02) in older children). Asymptomatic VDD had a modest but noticeable negative impact on HRQoL, attributed mostly to tiredness in both age groups and pain in the older paediatric population., Conclusions: Elicitation of HRQoL from clinical experts suggests a negative impact of VDD on HRQoL, even if there is no recognizable clinical manifestation. HRQoL data from populations of patients with MND will inform public health policy decisions. In some settings, routine collection of HRQoL data alongside national nutrition surveys may help capture the full burden of MND and prioritize resources towards effective prevention.

Objective: To assess sociodemographic, nutritional and health conditions associated with vitamin D sufficiency among young Brazilian children living at different latitudes., Design: Cross-sectional analysis with a four-level model of inflammation to correct micronutrient concentrations. Prevalence ratios (PR; 95 % CI) were estimated for factors associated with vitamin D sufficiency (≥50 nmol/l), adjusting for child's sex, age, skin colour, stunting and vitamin A+D supplementation., Setting: Primary health-care units in four Brazilian cities located at lower (7°59'26·9016″S and 9°58'31·3864″S) and higher latitudes (16°41'12·7752″S and 30°2'4·7292″S)., Participants: In total 468 children aged 11-15 months were included in the analysis., Results: Only 31·8 % of children were vitamin D sufficient (concentration <30 nmol/l and <50 nmol/l among 32·9 and 68·2 %, respectively). Living at higher latitudes was associated with reduced prevalence of vitamin D sufficiency compared with lower latitudes (PR = 0·65; 95 % CI 0·49, 0·85). Maternal education ≥9 years positively influenced a sufficient vitamin D status in children. After correction for inflammatory status, each increase of 1 µmol/l in vitamin A concentration was associated with a 1·38-fold higher prevalence of vitamin D sufficiency (95 % CI 1·18, 1·61). Progressive decline in the prevalence of vitamin D sufficiency was associated with marginal and deficient status of vitamin A (Ptrend = 0·001)., Conclusions: Lower latitude, higher maternal education and vitamin A concentration were positively associated with vitamin D sufficiency in young Brazilian children. These findings are relevant for planning public health strategies for improving vitamin D status starting in early infancy.

Objective: This study aimed to analyse the relationship between vitamin D deficiency and the season when the blood sample was obtained from subjects with chronic hepatitis C (CHC) infection., Design: A cross-sectional study was conducted on a representative sample. Vitamin D deficiency was defined as a serum 25-hydroxyvitamin D [25(OH)D] concentration <50 nmol/l, based on the values set forth by the Endocrine Society guideline for higher-risk populations. Seasonality was defined according to solstices and equinoxes. The association of seasonality and clinical/laboratory characteristics with vitamin D deficiency was assessed using a multivariate logistic regression analysis., Setting: NUPAIG Viral Hepatitis Outpatient Clinic of the Universidade Federal de São Paulo - Brazil., Participants: Adult subjects with CHC infection (n 306)., Results: The prevalence of vitamin D deficiency was 16 %, whereas the median serum 25(OH)D concentration was 87 (interquartile range, 59; third quartile = 118) nmol/l. Serum concentration was consistently lower in samples collected in spring and winter than in other seasons. In multivariate analysis, vitamin D deficiency was found to be independently associated with male gender, serum albumin concentration and with samples drawn in winter and spring., Conclusions: The findings show not only the relevance to consider season as a factor influencing 25(OH)D concentration but also the need to actively screen for hypovitaminosis D in all patients with CHC infection, especially in females and those with low albumin concentration.

Objective: Postpartum depression affects up to 20 % of new mothers within the first 12 months of parturition. 25-Hydroxyvitamin D (25(OH)D) has known importance in bone health, but it may also play an important role in other functions, including reproduction and fertility, immune function and mental health. This clinical commentary reviews literature evaluating 25(OH)D deficiency during pregnancy and the incidence of postpartum depressive symptomatology., Design: Narrative review, summary and recommendations., Setting/participants: A literature search revealed five relevant studies of antepartum women, three based in the USA, one in Turkey and one in Iran., Results: Three of the five studies measured serum 25(OH)D concentrations during the first or second trimester and discovered an association with 25(OH)D deficiency and depressive symptoms postpartum. One study determined an almost significant (P=0·058) inverse relationship with first-trimester 25(OH)D concentration and depressive symptoms postpartum, and the last study, which was a secondary analysis, did not find an association., Conclusions: The Endocrine Society recommends routine vitamin D supplementation during pregnancy and lactation due to increased metabolic demand in the mother, but a recent Cochrane review recommended against screening. Vitamin D should be the target of more studies during pregnancy and the postpartum period since it appears to have an important role for both medical and mental health. Vitamin D supplementation is a relatively safe and cost-effective intervention during pregnancy, and it may prove to be important in the prevention of postpartum depression.

Objective: We investigated the determinants of serum 25-hydroxyvitamin D [S-25(OH)D] and dietary vitamin D sources among three immigrant groups in Finland and compared their S-25(OH)D to the general Finnish population., Design: Cross-sectional population-based Migrant Health and Wellbeing Study and the nationally representative Finnish Health 2011 Survey. S-25(OH)D was standardised according to the Vitamin D Standardisation Program. Vitamin D sources were assessed by interview., Setting: Six different municipalities in Finland (60°-63°N)., Participants: Immigrants aged 18-64 years (446 Russians, 346 Somalis, 500 Kurds), 798 Finns aged 30-64 years., Results: The mean of S-25(OH)D was 64 (95 % CI 62, 66), 44 (95 % CI 41, 46), 35 (95 % CI 34, 37) and 64 (95 % CI 62, 66) nmol/l for Russians, Somalis, Kurds and Finns, respectively. S-25(OH)D among Somalis and Kurds was lower compared with Finns (P < 0·001). The prevalence of vitamin D deficiency (S-25(OH)D <30 nmol/l) and insufficiency (S-25(OH)D <50 nmol/l) was higher among immigrants than Finns (P < 0·001). Vitamin D-rich foods differed between the groups; vitamin D-fortified fat spread consumption was higher among Somalis (91 %) than among Russians (73 %) and Kurds (60 %); fish was less consumed among Kurds (17 %) than among Russians (43 %) and Somalis (38 %); and 57 % Russians, 56 % Kurds and 36 % Somalis consumed vitamin D-fortified dairy daily (P < 0·001 for all). Daily smoking, alcohol consumption and winter blood sampling were determinants of vitamin D insufficiency (P ≤ 0·03). Older age, physical activity, fish and vitamin D-fortified dairy consumption were associated with lower odds of insufficiency (P ≤ 0·04)., Conclusions: Vitamin D status differed among immigrant groups and the determinants are, to some degree, associated with learned or existing cultural behaviours.

Objective: Maternal vitamin D level in pregnancy may have implications for both the mother and fetus. Deficiency of vitamin D has been linked to several pregnancy complications and fetal skeletal health. Smoking has been associated with reduced serum level of the vitamin D metabolite, 25-hydroxyvitamin D (25(OH)D)., Design: A nested case-control study within the Finnish Maternity Cohort, a population-based cohort which includes first-trimester sera from 98 % of pregnancies in Finland since 1987. The selection consisted of women with uncomplicated pregnancies. We studied serum concentration of 25(OH)D in 313 non-smoking and forty-six self-reported smoking pregnant women., Setting: We hypothesize that pregnant smokers may have an increased risk of low 25(OH)D levels especially during winter months., Participants: A control group from an unpublished pregnancy complication study consisting of 359 uncomplicated pregnancies. Individuals who reported that they do not smoke were considered 'non-smokers' (n 313) and those who reported continued smoking after the first trimester of pregnancy were considered 'smokers' (n 46)., Results: Smokers had significantly lower levels of 25(OH)D irrespective of sampling time (P<0·0001). Furthermore, during the low sun-exposure season, only 14 % of smokers met the guideline level of 40 nmol/l for serum 25(OH)D in comparison with 31 % of non-smokers., Conclusions: Expectant mothers who smoke have an increased risk of vitamin D deficiency during low sun-exposure months in northern regions. Further studies are needed to assess the associated risks for maternal and fetal health as well as possible long-term implications for the infant.

Objective: A recent meta-analysis suggested that the association between vitamin D and risk of hypertension was markedly stronger in women aged <55 years in observational data, while the association became null in women aged ≥55 years. We therefore hypothesized that this difference in associations might potentially be caused by the change in oestrogen around menopause. Our objective was to investigate associations between vitamin D status and hypertension risk and to evaluate those associations as they may differ according to menopausal status., Design: A cross-sectional population survey conducted by the US Centers for Disease Control and Prevention, National Center for Health Statistics., Setting: The National Health and Nutrition Examination Surveys (NHANES) 2007-2010 formed the setting for the present study., Participants: We analysed data from 2098 premenopausal women and 2298 postmenopausal women., Results: After adjustment for sociodemographic, behavioural and dietary factors, higher concentrations both of serum total 25-hydroxyvitamin D (25(OH)D) and serum 25-hydroxycholecalciferol (25(OH)D3) revealed significant dose-dependent trends with lower risk of hypertension (Ptrend = 0·005 and 0·014, respectively) in premenopausal women. In those women, 25(OH)D ≥ 50 nmol/l (sufficient; in contrast to deficient, vitamin D < 30 nmol/l) appeared to have a protective effect against hypertension (OR = 0·64, 95 % CI 0·39, 1·02 for total 25(OH)D and OR = 0·60, 95 % CI 0·36, 1·00 for 25(OH)D3). Neither association with hypertension was observed in postmenopausal women., Conclusions: Serum 25(OH)D concentrations were associated with lower risk of hypertension in premenopausal women, but not in postmenopausal women.

Objective: To investigate the relationship between serum 25-hydroxyvitamin D (25(OH)D) and risk of incident diabetes in Hong Kong Chinese, after accounting for the effect of multiple bone- and mineral-related markers., Design: We conducted a retrospective study on the Hong Kong Osteoporosis Study cohort. Incident diabetes was ascertained using electronic medical records. Serum 25(OH)D was measured at baseline and its association with incident diabetes was evaluated using multivariable Cox proportional-hazard regression., Participants: Individuals (n 4342) aged 20 years or above (1395 men, 2947 women; mean age 54·3 (sd 16·5) years) from the Hong Kong Osteoporosis Study, who were free of diabetes at baseline, were included., Results: During 40 124·7 person-years of follow-up (a median of 9·2 years), 443 participants developed diabetes. Mean 25(OH)D was 63·34 (sd 13·07) nmol/l. Age-, sex- and BMI-adjusted Cox proportional-hazard regression showed no significant difference in the risk of incident diabetes between the lowest and the highest quintiles of 25(OH)D. In the analysis of the interaction effect between 25(OH)D and serum Ca, the interaction term did not affect the risk of incident diabetes significantly (P = 0·694). Similarly, there was no significant interaction of different subgroups (age, sex, BMI, femoral-neck T-score, serum Ca levels) with serum 25(OH)D., Conclusions: The present study finds that serum vitamin D level is not associated with the risk of incident diabetes in Hong Kong Chinese and this relationship is not modified by serum Ca level.

Objective: Both vitamin D and Fe micronutrient deficiencies are common in Saudi Arabia but the association between them is unclear. The present study aimed to determine whether Fe indices are associated with vitamin D status and other metabolic markers in Arab adolescents., Design: Single-centre, cross-sectional study gathering anthropometrics, glucose and lipid profile. Serum 25-hydroxyvitamin D (25(OH)D), Fe, total iron-binding capacity (TIBC), transferrin saturation (%) and other parameters were measured., Setting: Vitamin D School Project Database, King Saud University (2014-2016)., Participants: Arab adolescents aged 10-17 years randomly selected from the Vitamin D School Project Database (170 Saudi students; 100 girls, seventy boys)., Results: Among Fe indices, only TIBC was found to be significantly and inversely associated with 25(OH)D (r = -0·20; P < 0·01) and only in girls (r = -0·20; P < 0·05). Among cardiometabolic parameters, serum Fe was associated with TAG in boys (r = 0·36; P < 0·01) and inversely associated with HDL-cholesterol in girls (r = -0·29; P < 0·05). Age was the most significant predictor of serum Fe for all participants, accounting for 5 % (R2 = 0·05; P = 0·004) of variance perceived. Serum 25(OH)D and age, on the other hand, were the most significant predictors for TIBC, accounting for 10·1 % (R2 = 0·10; P < 0·001) of variance perceived., Conclusions: Among healthy Arab adolescents, the association between vitamin D and Fe indices, particularly TIBC, is modest, inverse and sex-dependent. Larger studies with inclusion of markers such as hepcidin and ferritin, vitamin D metabolites and endogenous sex hormones may provide a clearer view of this complex association.

Objective: To study plasma 25-hydroxyvitamin D (25(OH)D) status of children in Kerala, southern India, and its relationship with sociodemographic variables., Design: Cross-sectional observational study., Setting: Tertiary government hospital., Participants: Children (n 296) with trivial acute illness were enrolled. Sun exposure and Ca and vitamin D intakes (7 d dietary recall) were documented. Serum Ca, P, alkaline phosphatase, plasma 25(OH)D and parathyroid hormone (PTH) were measured., Results: Prevalence of vitamin D deficiency (plasma 25(OH)D <30 nmol/l) was 11·1% (median, interquartile range (IQR): 52·6, 38·4-65·6 nmol/l). Children who ate fish daily had significantly higher plasma 25(OH)D than those who did not (median, IQR: 52·5, 40·8-68·9 v. 49·1, 36·2-60·7 nmol/l; P = 0·02). Those investigated in the months of March-May showed highest 25(OH)D v. those enrolled during other times (median, IQR: 58·7, 45·6-81·4 v. 45·5, 35·6-57·4 nmol/l; P <0·001). Plasma 25(OH)D correlated positively with serum P (r = 0·24, P <0·001) and Ca intake (r = 0·16, P 0·03), negatively with age (r = -0·13, P 0·03) and PTH (r = -0·22, P <0·001.). On linear regression, summer season (March-May), lower age, daily fish intake and higher Ca intake were independently associated with plasma 25(OH)D., Conclusions: Prevalence of vitamin D deficiency is low in Kerala. The natural fish diet of coastal Kerala and the latitude may be protective. Public health policy in India should take account of this geographical diversity.

Objective: To explore the relationships of serum 25-hydroxyvitamin D (25(OH)D) with obesity and metabolic parameters in US children., Design: Cross-sectional analysis. We evaluated the associations between serum 25(OH)D and multiple measurements of adiposity, serum lipid concentrations, fasting glucose and insulin resistance in children aged 6-18 years with adjustments for multiple covariates., Setting: The National Health and Nutrition Examination Survey, 2001-2006., Participants: A nationally representative sample of 6311 children and adolescents aged 6-18 years., Results: Among US children and adolescents, the prevalence of vitamin D deficiency has been especially high in older children, girls and the non-Hispanic Black population. Higher odds of obesity were found at a 25(OH)D concentration of <30 nmol/l (deficiency) than at >50 nmol/l under both criteria for obesity in children (OR = 3·27, Ptrend ≤ 0.001). Moreover, increased odds of having abnormal HDL-cholesterol (OR = 1·71, Ptrend ≤ 0.001) and impaired insulin resistance (OR = 4·15, Ptrend ≤ 0·001) were found for children deficient in 25(OH)D compared with those with normal 25(OH)D concentrations. When the children and adolescents were stratified by gender, we found stronger associations between serum 25(OH)D concentration and both HDL-cholesterol and insulin resistance in girls. No association of 25(OH)D with any other metabolic parameter was found., Conclusions: Our results suggest a potential harmful association between low serum 25(OH)D concentration and the risk of obesity among children. However, the underlying mechanisms require further investigation.

Objective: To investigate serum 25-hydroxyvitamin D (S-25(OH)D) concentration in a multi-ethnic population of northern Norway and determine predictors of S-25(OH)D, including Sami ethnicity., Design: Cross-sectional data from the second survey of the Population-based Study on Health and Living Conditions in Regions with Sami and Norwegian Populations (the SAMINOR 2 Clinical Survey, 2012-2014). S-25(OH)D was measured by the IDS-iSYS 25-Hydroxy Vitamin Dˢ assay. Daily dietary intake was assessed using an FFQ. BMI was calculated using weight and height measurements., Setting: Ten municipalities of northern Norway (latitude 68°-70°N)., Participants: Males (n 2041) and females (n 2424) aged 40-69 years., Results: Mean S-25(OH)D in the study sample was 64·0 nmol/l and median vitamin D intake was 10·3 µg/d. The prevalence of S-25(OH)D<30 nmol/l was 1·9 % and <50 nmol/l was 24·7 %. In sex-specific multivariable linear regression models, older age, blood sample collection in September-October, solarium use, sunbathing holiday, higher alcohol intake (in females), use of cod-liver oil/fish oil supplements, use of vitamin/mineral supplements and higher intakes of vitamin D were significantly associated with higher S-25(OH)D, whereas being a current smoker and obesity were associated with lower S-25(OH)D. These factors explained 21-23 % of the variation in S-25(OH)D., Conclusions: There were many modifiable risk factors related to S-25(OH)D, however no clear ethnic differences were found. Even in winter, the low prevalence of vitamin D deficiency found among participants with non-Sami, multi-ethnic Sami and Sami self-perceived ethnicity was likely due to adequate vitamin D intake.

Objective: To investigate whether vitamin D status predicts weight gain or increase in waist circumference during the 11-year follow-up in general adult population., Design: A population-based longitudinal study., Setting: The study was conducted using data from the nationally representative Health 2000/2011 Survey. The analyses were based on regression models adjusted for sociodemographic and lifestyle factors., Participants: Weight, waist circumference and vitamin D status (serum 25-hydroxyvitamin D concentration analysed with radioimmunoassay) were measured from 2924 participants aged 30-64 years at baseline., Results: In men, low vitamin D status at baseline predicted ≥10 % increase in waist circumference during the follow-up when adjusted for age only (OR for sufficient v. deficient S-25(OH)D 0·41; 95 % CI 0·25, 0·67; P for trend <0·01), but the association with weight gain was only borderline significant. After adjustment for potential confounders, low vitamin D status remained a significant predictor of increase in waist circumference, but the association with weight gain was further attenuated. In women, vitamin D status at baseline did not predict weight gain or increase in waist circumference., Conclusions: Our results suggest that vitamin D insufficiency may be a risk factor of abdominal obesity among men but not among women. In men, it may also increase the risk of weight gain. Further studies are required to confirm these findings and examine potential mechanisms behind them. There is also a possibility that vitamin D is a biomarker of healthy lifestyle rather than an independent risk factor for obesity.

Objective: Numerous studies have reported an association between vitamin D (25-hydroxyvitamin D; 25(OH)D) deficiency and low economic status, lower educational level, drugs exposure, smoking and reduced physical activity. Our study analysed the association between sociodemographic factors and 25(OH)D status in Polish (Caucasian) seniors., Design: Cross-sectional study (part of the PolSenior study). Serum 25(OH)D concentration was measured by a solid-phase ELISA method; a standardized questionnaire evaluated educational level, economic status, alcohol consumption, current or past cigarette smoking, physical activity, activities of daily living (ADL) and instrumental activities of daily living., Setting: Community-dwelling randomly selected individuals aged 65 years or older, selected using three-stage stratified, proportional draw., Subjects: Seniors (n 3472; 1658 women and 1814 men)., Results: Mean serum 25(OH)D concentration was 20·5 (sd 9·6) ng/ml. Values below the recommended level (30 ng/ml) were detected in 82·8 % of men and 90·4 % of women. Regression analysis revealed that the difference between sexes was associated with decreased walking activity in women, probably resulting in less sunlight exposure. There was a positive association between any disability in ADL and the presence of vitamin D deficiency/insufficiency. In the sex-adjusted analysis, older age, alcohol abstinence and lack of cycling and long-distance walking were explanatory variables for vitamin D deficiency., Conclusions: Vitamin D deficiency/insufficiency is frequent in the older Polish population and associated with functional disability and impaired mobility of seniors.

Objective: To evaluate the association of vitamin D intake with dyslipidaemia and vitamin D insufficiency/deficiency in Brazilian children and identify the main food group sources of this nutrient in the sample., Design: A cross-sectional study carried out with a representative sample. Blood was collected after 12 h of fasting. Laboratory tests were performed to determine total cholesterol, HDL cholesterol (HDL-C), LDL cholesterol, TAG, apoB, apoA1, 25-hydroxyvitamin D and parathyroid hormone. Dietary intake was evaluated by a 24 h recall., Setting: Viçosa, Minas Gerais, Brazil., Subjects: Children between 8 and 9 years old enrolled in urban schools (n 378)., Results: We found an elevated prevalence of inadequate vitamin D intake (91·3 %), dyslipidaemia (72·8 %) and vitamin D insufficiency/deficiency (56·2 %). The food groups that contributed the most to vitamin D intake were dairy products and fish. Lower vitamin D intake was associated with increased prevalence of both low HDL-C (prevalence ratio=2·51; 95 % CI 1·02, 6·18; P<0·05) and vitamin D insufficiency/deficiency (prevalence ratio=1·61; 95 % CI 1·01, 2·58; P<0·05)., Conclusions: Given the elevated prevalence of inadequate vitamin D intake and its association with low HDL-C and vitamin D insufficiency/deficiency, it is important to develop specific actions in food and nutritional education as well as programmes that stimulate and facilitate access to vitamin D food sources, such as dairy products and fish.

Objective: To determine the prevalence and correlates of healthy vitamin D status in lactating Inuit women living in remote regions of the Arctic., Design: Cross-sectional., Setting: Households were selected randomly in thirty-six communities of Nunavut, Nunatsiavut and Inuvialuit Settlement Region. Dietary intake was assessed using a 24 h recall and an FFQ. Anthropometric measurements, household living conditions, supplement use and health status were assessed. In fasting samples, serum 25-hydroxyvitaimn D (25(OH)D) was measured using a chemiluminescent assay (LIAISON; Diasorin Inc.)., Subjects: Lactating Inuit women participating in the 2007-2008 International Polar Year Inuit Health Survey conducted in the months of August to October., Results: Among participants (n 34), 8·8, 26·5 and 50·0 % had 25(OH)D concentrations at or above 75, 50 and 40 nmol/l, respectively. More than one-third of participants did not consume traditional foods during the previous day and only 11·3 % of total energy intake was derived from traditional foods. Only 14·7 % of the sample consumed the daily number of milk servings recommended by Canada's Food Guide (two servings) for First Nations, Inuit and Métis. Using multivariable logistic regression to examine 25(OH)D≥40 nmol/l, only higher body fat was inversely correlated with 25(OH)D concentration., Conclusions: The present study is the first to assess simultaneously vitamin D status and other known factors that affect it among lactating Inuit women living in remote communities in the Arctic. Healthy maternal vitamin D status was observed in 25 % of participants during the late summer and early autumn. This requires further assessment in a larger sample spanning more seasons.

Objective: To investigate seasonal variations of vitamin D status at different latitudes and if these changes are accompanied by corresponding variations in certain health parameters in children living in a broad latitudinal range in Iran., Design: Longitudinal study., Subjects: In total, 530 apparently healthy children aged 5-18 years were randomly selected from six regions of Iran with a latitudinal gradient from 29°N to 37·5°N. All anthropometric and biochemical assessments were performed twice during a year (summer, winter). High BMI (Z-score >1), low HDL cholesterol (150 mg/dl) were considered cardiometabolic risk factors., Results: Serum 25-hydroxyvitamin D (25(OH)D) showed between-season variation, with significantly higher concentrations (mean (sd)) in summer v. winter (43 (29) v. 27 (18) nmol/l; P33°N v. <33°N: 4·5; 0·09, 9·0; P=0·04) were predictors of change of serum 25(OH)D between two seasons., Conclusions: Summertime improvement of vitamin D status was accompanied by certain improved cardiometabolic risk factors, notably serum TAG, total cholesterol and BMI, in children.

Objective: There is limited knowledge on vitamin D status of children residing in the Andes and its association with undernutrition. We evaluated the vitamin D status of children residing in a low socio-economic status (SES) setting in the Ecuadorian Andes and assessed the association between vitamin D status, stunting and underweight. We hypothesized that children who were underweight would have lower serum 25-hydroxyvitamin D (25(OH)D) levels and lower 25(OH)D levels would be associated with a higher risk of stunting., Design: We conducted a cross-sectional secondary analysis of a randomized controlled trial, the Vitamin A, Zinc and Pneumonia study. Children had serum 25(OH)D concentrations measured. A sensitivity analysis was undertaken to determine a vitamin D cut-off specific for our endpoints. Associations between serum 25(OH)D and underweight (defined as weight-for-age Z-score≤-1) and stunting (defined as height-for-age Z-score≤-2) were assessed using multivariate logistic regression., Setting: Children residing in five low-SES peri-urban neighbourhoods near Quito, Ecuador., Subjects: Children (n 516) aged 6-36 months., Results: Mean serum 25(OH)D concentration was 58·0 (sd 17·7) nmol/l. Sensitivity analysis revealed an undernutrition-specific 25(OH)D cut-off of <42·5 nmol/l; 18·6 % of children had serum 25(OH)D<42·5 nmol/l. Children who were underweight were more likely to have serum 25(OH)D<42·5 nmol/l (adjusted OR (aOR)=2·0; 95 % CI 1·2, 3·3). Children with low serum 25(OH)D levels were more likely to be stunted (aOR=2·8; 95 % CI 1·6, 4·7)., Conclusions: Low serum 25(OH)D levels were more common in underweight and stunted Ecuadorian children.

Objective: Pain-related conditions, such as chronic widespread pain and fibromyalgia, are major burdens for individuals and the health system. Evidence from previous research on the association between circulating 25-hydroxyvitamin D (25(OH)D) concentrations and pain is conflicting. Thus, we aimed to determine if there is an association between mean 25(OH)D concentration (primary aim), or proportion of hypovitaminosis D (secondary aim), and pain conditions in observational studies., Design: Published observational research on 25(OH)D concentration and pain-related conditions was systematically searched for in electronic sources (MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials) and a random-effects meta-analysis was conducted on included studies., Results: Eighty-one observational studies with a total of 50 834 participants were identified. Compared with controls, mean 25(OH)D concentration was significantly lower in patients with arthritis (mean difference (MD): -12·34 nmol/l; P<0·001), muscle pain (MD: -8·97 nmol/l; P=0·003) and chronic widespread pain (MD: -7·77 nmol/l; P<0·001), but not in patients with headache or migraine (MD: -2·53 nmol/l; P=0·06). The odds of vitamin D deficiency was increased for arthritis, muscle pain and chronic widespread pain, but not for headache or migraine, compared with controls. Sensitivity analyses revealed similar results., Conclusions: A significantly lower 25(OH)D concentration was observed in patients with arthritis, muscle pain and chronic widespread pain, compared with those without. These results suggest that low 25(OH)D concentrations may be associated with pain conditions.

Objective: To understand the relationship between vitamin D intake and serum 25-hydroxyvitamin D (25(OH)D) levels in a sample of Portuguese adolescents., Design: Cross-sectional evaluation carried out in the 2003/2004 school year. Vitamin D intake was assessed by an FFQ and 25(OH)D was measured in a fasting blood sample., Setting: Public and private schools in Porto, Portugal., Subjects: Adolescents aged 13 years (n 521) enrolled at school (EPITeen cohort)., Results: Both mean (sd) intake and serum 25(OH)D level were far below the recommended, 4·47 (2·49) µg/d and 16·5 (5·7) ng/ml, respectively. A significant difference in serum level was found according to season, with lower values in winter than summer (14·8 (4·6) v. 17·3 (5·9) ng/ml, P<0·001). Vitamin D intake was weakly correlated with serum 25(OH)D (r=0·056, P=0·203)., Conclusions: Dietary vitamin D and serum 25(OH)D levels were positively but weakly correlated and the error was higher among those with higher serum 25(OH)D concentration. Our results support the need for strategies that promote increase of the most important food sources of vitamin D to reduce the high prevalence of low vitamin D status.

Objective: To assess the prevalence of vitamin D insufficiency and deficiency and its association with cardiometabolic risk factors, controlled by adiposity, in a representative sample of prepubescent children., Design: Cross-sectional population-based study. Body composition was evaluated by dual-energy X-ray absorptiometry. Anthropometric measures and blood pressure were performed. Laboratory analyses were performed to determine the levels of vitamin D (25-hydroxyitamin D; 25(OH)D), glucose, insulin, serum lipids and intact parathyroid hormone. Dietary intake was assessed by three 24 h recalls., Setting: Viçosa, Minas Gerais, Brazil, 2015., Subjects: Representative sample of 378 children aged 8 and 9 years from urban schools., Results: Inadequate serum concentrations of 25(OH)D were diagnosed in more than half of the children and none of them met the recommended vitamin D intake. After adjusting for confounding factors in the multiple regression analysis, lower prevalence of insulin resistance and hypertriacylglycerolaemia was found in children with serum 25(OH)D levels ≥75 nmol/l (prevalence ratio=0·25; 95 % CI 0·08, 0·85) and ≥50 nmol/l (prevalence ratio=0·61; 95 % CI 0·37, 0·99), respectively. However, after adjusting for different indicators of adiposity, insulin resistance remained independently associated and the association with hypertriacylglycerolaemia was lost after adjusting for central adiposity. The prevalence of vitamin D insufficiency/deficiency was associated with the number of cardiometabolic alterations in children., Conclusions: The study results showed that prevalence of vitamin D insufficiency/deficiency was high among the children and insulin resistance was the main cardiometabolic alteration associated with this condition, even in a tropical climate country such as Brazil.

Objective: To determine the associations of sociodemographic characteristics, diet and outdoor activity as an indicator of sun exposure with serum 25-hydroxyvitamin D (25(OH)D) concentrations in children and their parents from Mesoamerica. We also quantified family aggregation of serum 25(OH)D., Design: Cross-sectional study. Serum 25(OH)D concentrations were quantified using immunoassay. We compared the distribution of 25(OH)D concentrations in adults and children by levels of each correlate with the use of linear regression. Family aggregation was estimated using Pearson and intraclass correlation coefficients., Setting: Capital cities of Guatemala, El Salvador, the Dominican Republic, Honduras, Nicaragua, Costa Rica, Panama and Belize, and Tuxtla Gutiérrez in Mexico., Subjects: Children (n 223) aged 7-12 years and 492 parents., Results: Mean (sd) 25(OH)D concentrations in adults and children were 81·3 (21·1) and 79·5 (18·1) nmol/l, respectively. Prevalence of vitamin D deficiency (VDD; 25(OH)D <50 nmol/l) was 3·9 % among adults and 3·6 % among children. In adults, adjusted mean 25(OH)D concentrations were highest in Nicaragua (P<0·0001). Serum 25(OH)D was positively related to time spent gardening (P=0·03). Among children, 25(OH)D concentrations were positively associated with male sex (P=0·005), dairy intake (P=0·03) and mother's serum 25(OH)D concentrations (P<0·0001); and inversely associated with mother's BMI (P=0·02) and number of home assets (P=0·04). Family membership explained 31 % of the variability in 25(OH)D concentrations; aggregation was highest between mothers and children., Conclusions: VDD prevalence was low in this study. Sociodemographic characteristics, diet and outdoor activity predict serum 25(OH)D. Family aggregation of serum 25(OH)D is high between mothers and children.

Objective: To determine the association of vitamin D status with depression and health-related quality of life among women., Design: This was a cross-sectional study conducted among women in Kuala Lumpur, Malaysia. Sociodemographic characteristics, physical activity status, perceived depression and health-related quality of life were assessed via a self-administered questionnaire. Fasting blood samples were taken for the analysis of 25-hydroxyvitamin D, parathyroid hormone, fasting blood glucose and full lipid profile. Complex samples multiple logistic regression analysis was performed., Setting: Public secondary schools in Kuala Lumpur, Malaysia., Subjects: Seven hundred and seventy female teachers were included., Results: The mean age of participants was 41·15 (95 % CI 40·51, 41·78) years and the majority were ethnic Malays. Over 70 % of them had vitamin D deficiency (<20 ng/ml or <50 nmol/l) and two-thirds were at risk for depression. In the multivariate analysis, ethnic Malays (adjusted OR (aOR)=14·72; 95 % CI 2·12, 102·21) and Indians (aOR=14·02; 95 % CI 2·27, 86·59), those at risk for depression (aOR=1·88, 95 % CI 1·27, 2·79) and those with higher parathyroid hormone level (aOR=1·13; 95 % CI 1·01, 1·26) were associated with vitamin D deficiency, while vitamin D deficiency was negatively associated with mental health-related quality of life (Mental Component Summary) scores (aOR=0·98; 95 % CI 0·97, 0·99)., Conclusions: Vitamin D deficiency is significantly associated with depression and mental health-related quality of life among women in Kuala Lumpur, Malaysia.

Objectives: To evaluate prevalence of vitamin D deficiency and its associated factors in southern Iranian children., Design: Cross-sectional study. Anthropometric and pubertal characteristics were assessed by a trained physician. Physical activity and sun exposure were evaluated using standard questionnaires. Body composition measurements were performed using dual-energy X-ray absorptiometry. Serum Ca, P alkaline phosphatase and 25-hydroxyvitamin D (25(OH)D) were assessed in all children. Statistical analysis was done using the statistical software package IBM SPSS Statistics 18·0., Subjects: Iranian children (n 477) aged 9-18 years., Setting: Fars Province, Iran, 2011., Results: Of the children, 81·3 % were 25(OH)D deficient. There was no significant difference in 25(OH)D concentration between boys and girls (P=0·3). 25(OH)D concentration was associated with BMI (r=-0·1, P=0·02), pubertal status (r=-0·08, P=0·04) and sun exposure (r=0·10, P=0·04). Fat mass index was associated with 25(OH)D concentration (r=-0·13, P=0·03), but not lean mass index (P=0·86). In multiple regression analysis with adjustment for confounding factors, age and puberty were found to be independently associated with 25(OH)D concentration (P=0·008 and P=0·006); there was a significant correlation between exercise and 25(OH)D concentration after adjustment for either BMI (P=0·01) or fat mass index (P=0·02)., Conclusions: 25(OH)D deficiency is highly prevalent among children in the south of Iran. It is related to insufficient sun exposure, low physical activity, advancing age and pubertal stage. Measures should be taken to improve the health of southern Iranian children in this critical age group by preventing 25(OH)D deficiency.

Objective: To assess vitamin D dietary sources, intake and 25-hydroxyvitamin D status and their association with individual and sociodemographic characteristics in Mexican children., Design: Data obtained from 2695 children aged 1-11 years from the Mexican National Health and Nutrition Survey (2012) were analysed. Diet was assessed by a 141-item FFQ. 25-Hydroxyvitamin D was measured by a chemiluminescent assay., Results: Mean vitamin D intake was 3·38 (se 0·09) µg/d (135·2 (se 3·6) IU/d) among pre-school children and 2·85 (se 0·06) µg/d (114·0 (se 2·4) IU/d) in school-age children. Milk accounted for 64·4 % of vitamin D intake in pre-school children and 54·7 % in school-age children. Vitamin D deficiency (serum 25-hydroxyvitamin D<50 nmol/l) was 25·9 % in pre-schoolers and 36·6 % in school-age children. Overweight/obese school-age children had a higher risk of vitamin D deficiency compared with normal-weight children (OR=2·23; 95 % CI 1·36, 3·66; P<0·05)., Conclusions: Vitamin D intakes are low in Mexican children, and milk is the main source of the vitamin. Vitamin D deficiency is common and associated with overweight in school-age children.

Objective: The objective of the present study was to determine if vitamin D intake and status are associated with pre-eclampsia in a country without a vitamin D fortification policy., Design: A case-control study of pregnancies with (case) and without (control) pre-eclampsia was conducted from January to April when UVB is minimal. Maternal and cord blood obtained at delivery were measured for plasma 25-hydroxycholecalciferol (25-OH-D3), 3-epimer of 25-OH-D3 (3-epi-25-OH-D3) and 24,25-dihydroxycholecalciferol (24,25-(OH)2D3) by LC-MS/MS and maternal 1,25-dihydroxyvitamin D (1,25-(OH)2D). Differences between groups were tested with ANOVA and Bonferroni post hoc tests (P<0·05)., Setting: Clinical Center of Serbia., Subjects: Pregnant women with and without pre-eclampsia (n 60) and their infants., Results: Exogenous vitamin D intake (0·95-16·25 µg/d (38-650 IU/d)) was not significantly different between groups. Women with pre-eclampsia delivered infants at an earlier gestational age and had significantly lower mean total plasma 25-hydroxyvitamin D (25-OH-D; case: 11·2 (sd 5·1); control: 16·1 (sd 5·7) ng/ml; P=0·0006), 25-OH-D3 (case: 10·0 (sd 4·9); control: 14·2 (sd 5·8) ng/ml; P=0·002), 3-epi-25-OH-D3 (case: 0·5 (sd 0·2); control: 0·7 (sd 0·2) ng/ml; P=0·0007) and 1,25-(OH)2D (case: 56·5 (sd 26·6); control: 81·0 (sd 25·7) pg/ml; P=0·018), while 24,25-(OH)2D3 was not different between groups. Infants did not differ in total plasma 25-OH-D, 25-OH-D3, 3-epi-25-OH-D3 and 24,25-(OH)2D3, but the mean proportion of 3-epi-25-OH-D3 was higher in the infant case group (case: 7·9 (sd 1·1); control: 7·0 (sd 1·4) % of total 25-OH-D3; P=0·005)., Conclusions: A high prevalence of vitamin D deficiency, as defined by plasma 25-OH-D<12 ng/ml, was observed in 47 % of all mothers and 77 % of all infants. These data underscore the need for prenatal vitamin D supplementation and a food fortification policy in Serbia.

Objective: To evaluate vitamin D deficiency prevalence and risk factors among pregnant Chinese women., Design: A descriptive cross-sectional analysis., Setting: China National Nutrition and Health Survey (CNNHS) 2010-2013., Subjects: A total of 1985 healthy pregnant women participated. Possible predictors of vitamin D deficiency were evaluated via multiple logistic regression analyses., Results: The median serum 25-hydroxyvitamin D level was 15·5 (interquartile range 11·9-20·0, range 3·0-51·5) ng/ml, with 74·9 (95 % CI 73·0, 76·7) % of participants being vitamin D deficient (25-hydroxyvitamin D <20 ng/ml). According to the multivariate logistic regression analyses, vitamin D deficiency was positively correlated with Hui ethnicity (P=0·016), lack of vitamin D supplement use (P=0·021) and low ambient UVB level (P<0·001). In the autumn months, vitamin D deficiency was related to Hui ethnicity (P=0·012) and low ambient UVB level (P<0·001). In the winter months, vitamin D deficiency was correlated with younger age (P=0·050), later gestational age (P=0·035), higher pre-pregnancy BMI (P=0·019), low ambient UVB level (P<0·001) and lack of vitamin D supplement use (P=0·007)., Conclusions: Vitamin D deficiency is prevalent among pregnant Chinese women. Residing in areas with low ambient UVB levels increases the risk of vitamin D deficiency, especially for women experiencing advanced stages of gestation, for younger pregnant women and for women of Hui ethnicity; therefore, vitamin D supplementation and sensible sun exposure should be encouraged, especially in the winter months. Further studies must determine optimal vitamin D intake and sun exposure levels for maintaining sufficient vitamin D levels in pregnant Chinese women.

Objective: We quantified the prevalence of vitamin D status in 6-24-month-old underweight and normal-weight children and identified the socio-economic and dietary predictors for status., Design: Cross-sectional, baseline data from a nutritional intervention study were analysed. Multinomial logistic regression was used to estimate the odds of being vitamin D deficient or insufficient with the reference being vitamin D sufficient., Setting: Urban slum area of Mirpur field site, Dhaka, Bangladesh., Subjects: Underweight (weight-for-age Z-score <-2·00) and normal-weight (weight-for-age Z-score ≥-1·00) children aged 6-24 months., Results: Among 468 underweight children, 23·1 % were sufficient, 42·3 % insufficient, 31·2 % deficient and 3·4 % severely vitamin D deficient. Among 445 normal-weight children, 14·8 % were sufficient, 39·6 % insufficient and 40·0 % deficient and 5·6 % severely deficient. With adjusted multinominal regression analysis, risk factors (OR (95 % CI)) for vitamin D deficiency in underweight children were: older age group (18-24 months old; 2·9 (1·5-5·7)); measurement of vitamin D status during winter (3·0 (1·4-6·4)) and spring (6·9 (3·0-16·1)); and maternal education (≥6 years of institutional education; 2·2 (1·0-4·9)). In normal-weight children, older age group (3·6 (1·2-10·6)) and living in the richest quintile (3·7 (1·1-12·5)) were found to be significantly associated with vitamin D insufficiency., Conclusions: The study demonstrates a significant burden of vitamin D insufficiency and deficiency in both underweight and normal-weight children <2 years of age from an urban slum of Bangladesh. Identification of risk factors may help in mitigating the important burden in such children.

Objective: Current US dietary recommendations for vitamin D vary by age. Recent research suggests that body weight and skin colour are also major determinants of vitamin D status. The objective of the present epidemiological investigation was to clarify the role of age as a predictor of vitamin D status, while accounting for body weight and skin colour, among a nationally representative sample., Design: We calculated the mean serum 25-hydroxyvitamin D levels for the US population by age and weight, as well as by weight and race/ethnicity group. Multiple regression analyses were utilized to evaluate age and weight as predictors of vitamin D status: serum 25-hydroxyvitamin D levels with age alone, age and body weight, and age, body weight and their two-way interaction were modelled for the entire sample and each age subgroup. Graphical data were developed using B-spline non-linear regression., Setting: National Health and Nutrition Examination Survey (31 934 unweighted cases)., Subjects: Individuals aged 1 year and older., Results: There were highly significant differences in mean vitamin D status among US residents by weight and skin colour, with those having darker skin colour or higher body weight having worse vitamin D status. Although a significant factor, the impact of age on vitamin D status was notably less than the impact of body weight., Conclusions: Vitamin D status varied predominantly by body weight and skin colour. Recommendations by nutritionists for diet and supplementation needs should take this into account if vitamin D-related health disparities are to be meaningfully reduced across the USA.

Objective: Although many studies worldwide have focused on the relationship between vitamin D and insulin resistance, results remain controversial. Furthermore, concentrations of serum 25-hydroxyvitamin D (25(OH)D) in the Chinese population are unclear. We aimed to investigate vitamin D status and its correlation with insulin resistance among a Chinese adult population., Design: Serum 25(OH)D, fasting blood glucose, fasting insulin, glycated Hb (HbA1c) and other metabolic parameters were assessed. Neck circumference, waist circumference, hip circumference, weight and height were also measured. Lifestyle factors including smoking and drinking status were obtained. Diabetes mellitus was diagnosed by HbA1c according to the 2010 American Diabetes Association criteria., Setting: Eastern China., Subjects: Of 7200 residents included, 6597 individuals were ultimately analysed., Results: We enrolled 2813 males (mean age 52·7 (sd 13·5) years) and 3784 females (52·3 (sd 13·5) years); mean serum 25(OH)D concentration was 43·1 (sd 11·6) and 39·6 (sd 9·8) nmol/l, respectively. Additionally, 83·3 % of participants were 25(OH)D deficient. A significant difference in 25(OH)D was observed between males and females in winter and spring (P<0·001). Furthermore, 25(OH)D concentrations were inversely associated with the homeostasis model assessment of insulin resistance (HOMA-IR) in the overweight and pre-diabetic populations. After adjusting for several variables, 25(OH)D was significantly associated with HOMA-IR in winter. When 25(OH)D values were categorized into quartiles, HOMA-IR was significantly associated with decreasing 25(OH)D., Conclusions: The majority of the Chinese population was vitamin D deficient and this deficiency was negatively associated with insulin resistance, particularly in the overweight and pre-diabetic populations. Moreover, these associations might be more evident in the winter.

Objective: The provision of prescribed vitamin D to all aged-care residents has been implemented in New Zealand as part of a government-led falls prevention programme. To our knowledge, there has been no evaluation of this universal programme on vitamin D status and functional and health outcomes. Thus, we aimed to determine 25-hydroxyvitamin D (25(OH)D) concentrations and their predictors in aged-care residents across the country and to investigate whether the government-funded programme was associated with adequate vitamin D status., Design: Cross-sectional survey of sociodemographic, biochemical, anthropometric, dietary and health characteristics. Blood samples were analysed for serum 25(OH)D and other biochemical measures. Multiple regression was used to examine predictors of vitamin D status., Setting: Sixteen residential aged-care facilities throughout New Zealand., Subjects: Residents aged ≥60 years with residency duration >12 weeks (n 309)., Results: Mean serum 25(OH)D was 89·9 (95 % CI 85·2, 94·5) nmol/l and monthly supplements (1250 µg (50 000 IU)) were taken by 75 % of all residents. Of those not taking a funded supplement, 65·3 % had serum 25(OH)D 125 nmol/l., Conclusions: Residents taking supplemental vitamin D had adequate vitamin D status; however monitoring of long-term supplementation should be considered, due to the high proportion of participants with high serum 25(OH)D levels.

Objective: Vitamin D plays a major role in Ca and bone metabolism, and its extraskeletal functions are being appraised. Although inadequate vitamin D concentrations have been reported in populations worldwide, too little is known about vitamin D status and its determinants among children in developing countries. We aimed to determine vitamin D status and its determinants in Nepalese children of pre-school age., Design: A community-based, cross-sectional study., Setting: Rural Nepal at latitude 27.39° N., Subjects: Healthy children (n 280) aged 12-60 months, selected randomly from the records of a vitamin A supplementation programme. Blood samples were collected using the dried blood spot technique and analysed for serum 25-hydroxyvitamin D (s-25(OH)D) concentration using liquid chromatography-tandem mass spectrometry. Ca intake and background variables were assessed with a structured questionnaire., Results: Hypovitaminosis D, defined as s-25(OH)D concentration less than 50 nmol/l, was found in 91.1% of the children. S-25(OH)D concentration was not related to gender, socio-economic indicators, sun exposure or nutritional status. Currently breast-fed children had higher s-25(OH)D concentrations (36.4 (sd 13.2) nmol/l) than those who were not (28.6 (sd 9.8) nmol/l, P<0.001). Adjustment for sociodemographic factors did not alter the results., Conclusion: There is widespread vitamin D deficiency among pre-school children in a rural area of Nepal. In our sample, sociodemographic factors did not affect the vitamin D status of children, but prolonged breast-feeding was associated with higher s-25(OH)D concentrations. Further research is required to investigate the health consequences of poor vitamin D status for this population.

Objective: We examined associations between the frequency of fruit and vegetable (F&V) consumption and nutritional deficiencies among Brazilian schoolchildren., Design: A cross-sectional, population-based study was performed. A short FFQ was used to assess consumption of fruits and vegetables (F&V) over the past month. The prevalence ratios (PR) and 95 % confidence intervals for stunting, obesity, anaemia, vitamin A and folate deficiencies, vitamin E and vitamin D insufficiencies were estimated for low F&V consumption frequency (vegetables ≤ 3 times/month and fruits ≤ 3 times/week) and compared with children with usual F&V consumption frequency (vegetables ≥ 1 time/week and fruits ≥ 4 times/week)., Setting: Acrelândia, Western Brazilian Amazon., Subjects: A total of 702 children aged 4-10 years., Results: Only 5 % of children consumed F&V ≥ 5 times/d. Prevalence of deficiency was 31 %, 15 %, 9 % and 2 % for vitamins D, A, E and folate, respectively. Overall, 6.3% of children were anaemic, 3.3% were stunted, 2.7% were obese and 33 % had multiple nutritional deficiencies. Low frequency of F&V consumption was associated with lower plasma concentrations of carotenoids and vitamin E. Nutritional deficiencies were higher among non-consumers of F&V when compared with usual consumers: anaemia (PR=1.9; 95 % CI 1.0, 3.7), vitamin E insufficiency (PR=2.5; 95% CI 1.5, 4.2), vitamin D insufficiency (PR=1.5; 95% CI 1.1, 1.9) and stunting (PR=2.6; 95% CI 1.1, 6.1)., Conclusions: In our study, the occurrence of nutritional deficiencies in children with low F&V consumption was twice as high as in children with usual F&V consumption, reinforcing the importance of effective actions to promote the consumption of F&V.

Objective: Black and Hispanic individuals synthesize less vitamin D per unit of sun exposure than white individuals. The relationship between UV radiation and vitamin D insufficiency in minorities has not been well explored., Design: Prospective cohort study., Setting: Using the National Health and Nutrition Examination Survey, we obtained serum vitamin D levels for non-Hispanic Whites, Hispanics and non-Hispanic Blacks aged ≥18 years from 2000-2006. We linked these data with the average monthly solar UV index by census tract and data on sun exposure, vitamin D supplementation, health and demographics. We used multivariable regression analyses to assess vitamin D deficiency (<15 ng/ml) and insufficiency (<20 ng/ml) in January (when the UV index was lowest) by race/ethnicity and geography., Subjects: Adults (n 14,319) aged ≥18 years., Results: A 1-point increase in the UV index was associated with a 0·51 ng/ml increase in vitamin D (95% CI 0·35, 0·67 ng/ml; P<0·001). Non-Hispanic Black race and Hispanic ethnicity were associated with a 7·47 and 3·41 ng/ml decrease in vitamin D, respectively (both P<0·001). In January, an estimated 65·4% of non-Hispanic Blacks were deficient in vitamin D, compared with 28·9% of Hispanics and 14·0% of non-Hispanic Whites. An estimated 84·2% of non-Hispanic Blacks were insufficient in vitamin D v. 56·3% of Hispanics and 34·8% of non-Hispanic Whites. More non-Hispanic Blacks were estimated to be deficient in vitamin D in January in the highest UV index quartile than were non-Hispanic Whites in the lowest UV index quartile (60·2% v. 25·7%)., Conclusions: Wintertime vitamin D insufficiency is pervasive among minority populations, and not uncommon among non-Hispanic Whites.

Objective: To assess vitamin D status among Cypriot adolescents and investigate potential determinants including BMI and body fat percentage (BF%)., Design: Participants had cross-sectional assessments of serum vitamin D, physical activity, dietary vitamin D intake and sun exposure. Linear and logistic regression models were used to explore the associations of vitamin D with potential predictors., Setting: Hospitals, Cyprus, November 2007-May 2008., Subjects: Adolescents (n 671) aged 16-18 years., Results: Mean serum vitamin D was 22·90 (sd 6·41) ng/ml. Only one in ten children had sufficient levels of vitamin D (≥30 ng/ml), while the prevalence of vitamin D deficiency (12-20 ng/ml) and severe deficiency (<12 ng/ml) was 31·7 % and 4·0 %, respectively. Lower vitamin D was associated with winter and spring season, female gender, reduced sun exposure in winter and darker skin. Participants with highest BMI and BF% when compared with a middle reference group had increased adjusted odds of vitamin D insufficiency (OR = 3·00; 95 % CI 1·21, 7·45 and OR = 5·02; 95 % CI 1·80, 13·97, respectively). A similar pattern, although not as strong, was shown for vitamin D deficiency with BF% (OR = 1·81; 95 % CI 1·04, 3·16) and BMI (OR = 1·51; 95 % CI 0·85, 2·67). Participants in the lowest BMI and BF% groups also displayed compromised vitamin D status, suggesting a U-shaped association., Conclusions: Vitamin D deficiency in adolescence is very prevalent in sunny Cyprus, particularly among females, those with darker skin and those with reduced sun exposure in winter. Furthermore, vitamin D status appears to have a U-shaped association with adiposity measures.

Objective: The present study aimed to review the literature on micronutrient deficiency and other factors influencing a deficiency status among children living in China., Design: A systematic review was performed to analyse the literature., Setting: Studies were identified through a search of PubMed and secondary references., Subjects: Children living in China aged less than 18 years., Results: Sixty-one articles were included. The prevalence of vitamin A deficiency decreased to approximately 10 % in 1995-2009. It increased with age but no significant difference was found between genders. The prevalence of thiamin and vitamin B12 deficiency was 10·5 % in Yunnan and 4·5 % in Chongqing provinces, respectively. Higher vitamin D deficiency rates were seen in spring and winter. The incidence of bleeding due to vitamin K deficiency was 3·3 % in 1998-2001 and more prevalent in rural areas. Both iodine deficiency and excess iodine intake were observed. Goitre rates were reported in Tibet, Jiangxi, Gansu and Hong Kong (3·5-46 %). Anaemia rates ranged from 20 % to 40 % in 2007-2011. High Se deficiency rates were found in Tibet, Shaanxi and Jiangsu. High Zn deficiency rates were also found (50-70 %) in 1995-2006. Few studies reported Ca deficiency rates (19·6-34·3 %). The degrees of deficiency for vitamin A, vitamin B12, Fe and Zn were more substantial in rural areas compared with urban areas., Conclusions: The prevalence of micronutrient deficiency rates varied. Socio-economic status, environmental factors and the Chinese diet may influence micronutrient deficiency. Public health policies should consider implementing programmes of supplementation, food fortification and nutrition education to address these deficiencies among Chinese children.

Objective: In 2011, the U.S. Institute of Medicine updated the definition of vitamin D inadequacy to serum 25-hydroxyvitamin D (25(OH)D) concentration of 30-<50 nmol/l and of deficiency to serum 25(OH)D < 30 nmol/l. We describe the prevalence of these conditions according to these definitions, seasonal variation in 25(OH)D and predictors of serum 25(OH)D concentrations among working, white women., Design: Participants recorded lifestyle factors and dietary intake and provided fasting blood samples for measurement of serum 25(OH)D in both summer and winter. Predictors of serum 25(OH)D variation were analysed using linear regression and generalized linear mixed models., Setting: Kingston General Hospital in Kingston, Ontario, Canada, from April 2008 to July 2009., Subjects: Female premenopausal nurses (n 83) working full-time rotating shifts., Results: Deficient or inadequate vitamin D status was observed in 9% of participants following summer/autumn and in 13% following winter/spring. Predictors of serum 25(OH)D concentration were vitamin D supplement use, tanning bed use and season. Tanning bed use increased serum 25(OH)D by 23.24 nmol/l (95% CI 8.78, 37.69 nmol/l, P = 0.002) on average., Conclusions: According to the 2011 Institute of Medicine bone health guidelines, over 10% of nurses had deficient or inadequate vitamin D status following winter. Higher serum concentrations were associated with use of tanning beds and vitamin D supplements. As health promotion campaigns and legal restrictions are successful in reducing tanning bed use among women, our data suggest that increased prevalence of vitamin D inadequacy and deficiency may be a consequence, and that low vitamin D status will need to be countered with supplementation.

Objective: To describe vitamin D intakes in children and teenagers and the contribution from supplements and fortified foods in addition to the base diet., Design: Analysis of 7 d weighed food records collected during the Children's and Teens' National Nutrition Surveys in Ireland. Food composition data for vitamin D were updated from international analytical sources., Setting: Nationally representative cross-sectional dietary surveys., Subjects: Children (n 594; 5-12 years) and teenagers (n 441; 13-17 years)., Results: Median vitamin D intakes were 1.9, 2.1 and 2.4 μg/d in 5-8-, 9-12- and 13-17-year-olds, respectively. The prevalence of vitamin D-containing supplement use was 21, 16 and 15% in 5-8-, 9-12- and 13-17-year-olds and median intakes in users ranged from 6.0 to 6.7 μg/d. The prevalence of inadequate intakes, defined as the percentage with mean daily intakes below the Estimated Average Requirement of 10 μg/d, ranged from 88 to 96% in supplement users. Foods fortified with vitamin D, mainly breakfast cereals, fat spreads and milk, were consumed by 71, 70 and 63 % of 5-8-, 9-12- and 13-17-year-olds. Non-supplement users who consumed vitamin D-fortified foods had median intakes of 1.9-2.5 μg/d, compared with 1.2-1.4 μg/d in those who did not consume fortified foods., Conclusions: It is currently not possible for children consuming the habitual diet to meet the US Institute of Medicine dietary reference intake for vitamin D. In the absence of nationally representative 25-hydroxyvitamin D data in children, the implications of this observation for prevalence of vitamin D deficiency and health consequences are speculative.

Objective: To evaluate the prevalence of vitamin D deficiency and predictors for low vitamin D status in Korean adolescents living between latitudes 33° and 39° N., Design: A descriptive cross-sectional study., Setting: Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2009., Subjects: A total of 1510 healthy adolescents aged 12-18 years (806 male, mean age 14.7 years) participated. Possible predictors for low vitamin D status (log-transformed 25-hydroxyvitamin D (25(OH)D) concentrations) were evaluated., Results: The prevalence of vitamin D deficiency (25(OH)D<20 ng/ml) was 89.1% in spring, 53.7% in summer, 63.9% in autumn and 90.5% in winter. Winter season, older age, higher education level reached, being female, being obese, a lack of vitamin D supplementation, lower milk consumption (0-<200 ml/d) and a lack of physical activity were unadjusted predictors (all P < 0.05). Multiple linear regression analysis showed that winter season (P < 0.001), higher education level (P < 0.001) and a lack of vitamin D supplementation (P = 0.012) were independent predictors for low vitamin D status. The modifying effect of season on the association between vitamin D supplement use and vitamin D status was significant (P < 0.001)., Conclusions: Vitamin D deficiency was highly prevalent in Korean adolescents, especially those in higher school grades. Vitamin D supplementation may contribute to maintain a better vitamin D status with lower seasonal variation. Further studies are required to determine optimal vitamin D intakes to maintain sufficient vitamin D status for Korean adolescents.

Objective: The present study aimed to evaluate the frequency of deficiency/insufficiency of vitamin D in adolescents and its relationship to overweight and metabolic disorders., Design: Cross-sectional study. Nutritional status was assessed by BMI according to WHO recommendations. Dietary intake was evaluated using a 3 d dietary record. The biochemical evaluation comprised measurements of serum lipids, lipoproteins, glucose, insulin, calcidiol (25(OH)D) and parathyroid hormone. Insulin resistance was calculated using the homeostasis model assessment. Body composition and blood pressure were assessed., Setting: Fifteen schools (eight public and seven private) in the central city of Juiz de Fora, Brazil., Subjects: The analysis included a study population of 160 adolescents (seventy-seven eutrophic and eighty-three overweight) aged 15 to 17 years., Results: Vitamin D deficiency and insufficiency was observed in 1.25 and 70.6 % of adolescents, respectively. Serum 25(OH)D levels were statistically lower in adolescents with weight excess, abdominal obesity, hypercholesterolaemia, higher levels of parathyroid hormone, insulin resistance, hyperinsulinaemia and hypertension (P < 0.05). Lower BMI and waist circumference were observed in the third (highest) tertile of vitamin D intake for all adolescents. The high prevalence of vitamin D insufficiency is primarily nutritional and reflects a low vitamin D intake., Conclusions: Our results support the negative association among serum 25(OH)D levels and vitamin D intake with non-skeletal outcomes in Brazilian adolescents. Vitamin D fortification of foods and/or the use of vitamin D supplements need to be considered to raise vitamin D intake in the adolescent population, even in a sunny country like Brazil.

Many studies have investigated the aetiological roles of genetic and environmental factors in coeliac disease (CD) with the long-term goal of developing an effective primary prevention strategy. CD is a condition with dysregulated systemic and intestinal mucosal immune responses to dietary gluten proteins among genetically predisposed individuals. We recently described spring birth as a novel risk factor for CD in children. We believe that the association between season of birth and CD is due to seasonal differences in sunlight exposure and subsequent vitamin D status. Concomitant with global increases in CD prevalence, vitamin D deficiency also is increasingly recognized in children worldwide. Recent studies have shown that vitamin D deficiency can cause improper immune responses, abnormal intestinal mucosal integrity and impaired local defence to pathogenic microbial agents. In conjunction with other potential aetiological factors, we propose a hypothesis model of early-life vitamin D deficiency in the pathogenesis of childhood-onset CD.