scholarly journals Weight and skin colour as predictors of vitamin D status: results of an epidemiological investigation using nationally representative data

2016 ◽  
Vol 20 (10) ◽  
pp. 1857-1864 ◽  
Author(s):  
Sonali Rajan ◽  
Tom Weishaar ◽  
Bryan Keller

AbstractObjectiveCurrent 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.DesignWe 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.SettingNational Health and Nutrition Examination Survey (31 934 unweighted cases).SubjectsIndividuals aged 1 year and older.ResultsThere 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.ConclusionsVitamin 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.

2020 ◽  
Author(s):  
Zhenzhen Wan ◽  
Jingyu Guo ◽  
An Pan ◽  
Chen Chen ◽  
Liegang Liu ◽  
...  

<b>Objective: </b>The evidence regarding vitamin D status and mortality among diabetes is scarce. This study aimed to examine the association of serum 25-hydroxyvitamin D [25(OH)D] concentrations with all-cause and cause-specific mortality among adults with <a>diabetes mellitus</a>. <p><b>Research Design and Methods: </b>This study included 6329 adults with diabetes from the Third National Health and Nutrition Examination Survey (NHANES III) and NHANES 2001-2014. Death outcomes were ascertained by linkage to National Death Index records through 31 December 2015. Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence (CIs) for mortality from all causes, cardiovascular disease (CVD), and cancer.</p> <p><b>Results:</b> The weighted mean (95% CI) level of serum 25(OH)D was 57.7 (56.6, 58.8) nmol/L, and 46.6% had deficient vitamin D (<50 nmol/L [20 ng/mL]). <a>Higher </a>serum 25(OH)D levels were significantly associated with lower levels of glucose, insulin, HOMA-IR, HbA1c, blood lipids, and C-reactive protein at baseline (all <i>P</i><sub>trend</sub><0.05). During 55126 person-years of follow-up, 2056 deaths were documented, including 605 CVD deaths and 309 cancer deaths. <a>After multivariate adjustment, higher </a>serum 25(OH)D levels were significantly and linearly associated with lower all-cause and CVD mortality: there was a 31% reduced risk of all-cause mortality and a 38% reduced risk of CVD mortality per one unit increment in natural log-transformed 25(OH)D (both <i>P</i><0.001). Compared with participants with 25(OH)D <25 nmol/L, the multivariate-adjusted HRs and 95% CI for participants with 25(OH)D >75 nmol/L were 0.59 (0.43, 0.83) for all-cause mortality (<i>P</i><sub>trend</sub>=0.003), 0.50 (0.29, 0.86) for CVD mortality (<i>P</i><sub>trend</sub>=0.02), and 0.49 (0.23, 1.04) for cancer mortality (<i>P</i><sub>trend</sub>=0.12). </p> <p><b>Conclusions: </b>In a nationally representative sample of US adults with diabetes, higher serum 25(OH)D levels were significantly associated with lower all-cause and CVD mortality. These findings suggest that maintaining adequate vitamin D status may lower mortality risk in individuals with diabetes.</p>


Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3872
Author(s):  
Soriah M. Harvey ◽  
Vanessa E. Murphy ◽  
Peter G. Gibson ◽  
Michael Clarke ◽  
Megan E. Jensen

Measurement of vitamin D status has significant use in clinical and research settings, including during pregnancy. We aimed to assess the agreement of total 25-hydroxyvitamin D (25(OH)D) concentration, and its three analytes (25-hydroxyvitamin D3 (25(OH)D3), 25-hydroxyvitamin D2 (25(OH)D2) and Epi-25-hydroxyvitamin D3 (Epi-25(OH)D3)), in plasma and serum samples collected during pregnancy, and to examine the proportion of women who change vitamin D status category based on sample type. Matching samples were collected from n = 114 non-fasting women between 12–25 weeks gestation in a clinical trial in Newcastle, Australia. Samples were analysed by liquid chromatography-tandem mass-spectrometry (LC-MS/MS) to quantify total 25(OH)D and its analytes and examined using Bland-Altman plots, Pearson correlation (r), intraclass correlation coefficient and Cohen’s Kappa test. Serum total 25(OH)D ranged from 33.8–169.8 nmol/L and plasma ranged from 28.6–211.2 nmol/L. There was a significant difference for total 25(OH)D based on sample type (measurement bias 7.63 nmol/L for serum vs plasma (95% Confidence Interval (CI) 5.36, 9.90, p ≤ 0.001). The mean difference between serum and plasma concentrations was statistically significant for 25(OH)D3 (7.38 nmol/L; 95% CI 5.28, 9.48, p ≤ 0.001) and Epi-25(OH)D3 (0.39 nmol/L; 95% CI 0.14, 0.64, p = 0.014). Of 114 participants, 28% were classified as vitamin D deficient (<50 nmol/L) or insufficient (<75 nmol/L) based on plasma sample and 36% based on serum sample. Nineteen (16.7%) participants changed vitamin D status category based on sample type. 25-hydroxyvitamin D quantification using LC-MS/MS methodology differed significantly between serum and plasma, yielding a higher value in plasma; this influenced vitamin D status based on accepted cut-points, which may have implications in clinical and research settings.


2014 ◽  
Vol 112 (7) ◽  
pp. 1081-1087 ◽  
Author(s):  
Joy Y. Zhang ◽  
Alice J. Lucey ◽  
Richard Horgan ◽  
Louise C. Kenny ◽  
Mairead Kiely

Nutritional requirements for vitamin D during pregnancy have been inadequately described, and there are conflicting data on the impact of gestation on vitamin D status. In the present study, we conducted a longitudinal analysis of total and free (unbound) serum 25-hydroxyvitamin D (25(OH)D), vitamin D-binding protein (DBP) and albumin concentrations in a random sample of thirty women from the Screening for Pregnancy Endpoints Ireland pregnancy cohort study at 15, 20, 24, 28, 32, 36 and 40 weeks of gestation and at 2 months postpartum. Concentrations of serum 25(OH)D, DBP and albumin were determined, and free 25(OH)D was calculated from the concentrations of total 25(OH)D, DBP and albumin. Serum albumin concentration decreased during pregnancy (P< 0·001), with a nadir at 36 weeks (P< 0·005), during which the concentration was approximately 80 % of the postnatal concentration. Serum DBP concentration increased during pregnancy and at 28 weeks of gestation, which was almost double the postnatal level (P< 0·001). Total and free 25(OH)D concentrations decreased (bothP< 0·005) as pregnancy progressed, and both were lowest at 36 weeks of gestation. At 15 weeks, 10 and 63 % of the women had serum 25(OH)D concentration < 30 and 50 nmol/l, respectively, which increased to 53 and 80 % at 36 weeks of gestation. The time course of decreasing concentrations of 25(OH)D during gestation among women recruited during May–July, who delivered between October and November, and among those recruited in August–September, who delivered between February and March, was similar. The lower percentage of free 25(OH)D during pregnancy is mainly due to increased DBP.


2020 ◽  
Author(s):  
Zhenzhen Wan ◽  
Jingyu Guo ◽  
An Pan ◽  
Chen Chen ◽  
Liegang Liu ◽  
...  

<b>Objective: </b>The evidence regarding vitamin D status and mortality among diabetes is scarce. This study aimed to examine the association of serum 25-hydroxyvitamin D [25(OH)D] concentrations with all-cause and cause-specific mortality among adults with <a>diabetes mellitus</a>. <p><b>Research Design and Methods: </b>This study included 6329 adults with diabetes from the Third National Health and Nutrition Examination Survey (NHANES III) and NHANES 2001-2014. Death outcomes were ascertained by linkage to National Death Index records through 31 December 2015. Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence (CIs) for mortality from all causes, cardiovascular disease (CVD), and cancer.</p> <p><b>Results:</b> The weighted mean (95% CI) level of serum 25(OH)D was 57.7 (56.6, 58.8) nmol/L, and 46.6% had deficient vitamin D (<50 nmol/L [20 ng/mL]). <a>Higher </a>serum 25(OH)D levels were significantly associated with lower levels of glucose, insulin, HOMA-IR, HbA1c, blood lipids, and C-reactive protein at baseline (all <i>P</i><sub>trend</sub><0.05). During 55126 person-years of follow-up, 2056 deaths were documented, including 605 CVD deaths and 309 cancer deaths. <a>After multivariate adjustment, higher </a>serum 25(OH)D levels were significantly and linearly associated with lower all-cause and CVD mortality: there was a 31% reduced risk of all-cause mortality and a 38% reduced risk of CVD mortality per one unit increment in natural log-transformed 25(OH)D (both <i>P</i><0.001). Compared with participants with 25(OH)D <25 nmol/L, the multivariate-adjusted HRs and 95% CI for participants with 25(OH)D >75 nmol/L were 0.59 (0.43, 0.83) for all-cause mortality (<i>P</i><sub>trend</sub>=0.003), 0.50 (0.29, 0.86) for CVD mortality (<i>P</i><sub>trend</sub>=0.02), and 0.49 (0.23, 1.04) for cancer mortality (<i>P</i><sub>trend</sub>=0.12). </p> <p><b>Conclusions: </b>In a nationally representative sample of US adults with diabetes, higher serum 25(OH)D levels were significantly associated with lower all-cause and CVD mortality. These findings suggest that maintaining adequate vitamin D status may lower mortality risk in individuals with diabetes.</p>


2017 ◽  
Vol 118 (4) ◽  
pp. 263-272 ◽  
Author(s):  
Emma T. Callegari ◽  
Suzanne M. Garland ◽  
Alexandra Gorelik ◽  
Nicola J. Reavley ◽  
John D. Wark

AbstractVitamin D deficiency is a global public health concern. Studies of serum 25-hydroxyvitamin D (25(OH)D) determinants in young women are limited and few include objective covariates. Our aims were to define the prevalence of vitamin D deficiency and examine serum 25(OH)D correlates in an exploratory study of women aged 16–25 years. We studied 348 healthy females living in Victoria, Australia, recruited through Facebook. Data collected included serum 25(OH)D assayed by liquid chromatography-tandem MS, relevant serum biochemistry, soft tissue composition by dual-energy X-ray absorptiometry, skin melanin density, Fitzpatrick skin type, sun exposure using UV dosimeters and lifestyle factors. Mean serum 25(OH)D was 68 (sd27) nmol/l and 26 % were vitamin D deficient (25(OH)D <50 nmol/l). The final model explained 56 % of 25(OH)D variance. Serum sex hormone-binding globulin levels, creatinine levels, sun exposure measured by UV dosimeters, a positive attitude towards sun tanning, typically spending >2 h in the sun in summer daily, holidaying in the most recent summer period, serum Fe levels, height and multivitamin use were positively associated with 25(OH)D. Fat mass and a blood draw in any season except summer was inversely associated with 25(OH)D. Vitamin D deficiency is common in young women. Factors such as hormonal contraception, sun exposure and sun-related attitudes, as well as dietary supplement use are essential to consider when assessing vitamin D status. Further investigation into methods to safely optimise vitamin D status and to improve understanding of the impact of vitamin D status on long-term health outcomes is required.


2008 ◽  
Vol 99 (5) ◽  
pp. 1061-1067 ◽  
Author(s):  
Tom R. Hill ◽  
Alice A. Cotter ◽  
Sarah Mitchell ◽  
Colin A. Boreham ◽  
Werner Dubitzky ◽  
...  

Despite recent concerns about the high prevalence of sub-clinical vitamin D deficiency in adolescents, relatively few studies have investigated the underlying reasons. The objective of the present study was to investigate the prevalence and predictors of vitamin D inadequacy among a large representative sample of adolescents living in Northern Ireland (54–55°N). Serum concentrations of 25-hydroxyvitamin D (25(OH)D) were analysed by enzyme-immunoassay in a subgroup of 1015 of the Northern Ireland Young Hearts 2000 cohort; a cross-sectional study of 12 and 15 year-old boys and girls. Overall mean 25(OH)D concentration throughout the year was 64·3 (range 5–174) nmol/l; 56·7 and 78·1 nmol/l during winter and summer, respectively. Reported intakes of vitamin D were very low (median 1·7 μg/d). Of those adolescents studied, 3 % and 36 % were vitamin D deficient and inadequate respectively, as defined by serum 25(OH)D concentrations < 25 and < 50 nmol/l. Of the subjects, 46 % and 17 % had vitamin D inadequacy during winter and summer respectively. Gender differences were also evident with 38 % and 55 % of boys and girls respectively classified as vitamin D inadequate during winter (P < 0·001). Predictors of vitamin D inadequacy during winter were vitamin D intake and gender. In conclusion, there is a high prevalence of vitamin D inadequacy in white-skinned adolescents in Northern Ireland, particularly during wintertime and most evident in girls. There is a clear need for dietary recommendations for vitamin D in this age group and for creative strategies to increase overall vitamin D status in the population.


Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 573
Author(s):  
Naoko Tsugawa ◽  
Mayu Nishino ◽  
Akiko Kuwabara ◽  
Honami Ogasawara ◽  
Maya Kamao ◽  
...  

Background: Breast milk is considered the optimal source of nutrition during infancy. Although the vitamin D concentration in human breast milk is generally considered poor for infants, vitamin D in breast milk is an important source for exclusively breastfed infants. Increases in vitamin D insufficiency and deficiency in lactating mothers may reduce vitamin D concentrations in breast milk. This study aimed to compare vitamin D and 25-hydroxyvitamin D (25OHD) concentrations in breast milk collected in 1989 and 2016–2017 and simultaneously analyze them with liquid chromatography-tandem mass spectrometry (LC-MS/MS); the association between the lifestyle of recent lactating mothers (2016–2017) and vitamin D status in human breast milk was also evaluated. Method: Lactating mothers were recruited from three regions of Japan in 1989 (n = 72) and 2016–2017 (n = 90), and milk from 3–4 months was collected in summer and winter. The samples were strictly sealed and stored at −80℃ until measurement. Breast milk vitamin D and 25OHD concentrations were analyzed by LC-MS/MS. Vitamin D intake, sun exposure, and sunscreen use of the lactating mothers in 2016–2017 were assessed. Results: Both vitamin D and 25OHD concentrations in breast milk were higher in the summer regardless of the survey year. Significantly lower vitamin D and 25OHD concentrations were observed in 2016–2017 compared with 1989 in summer, but no survey year difference was observed in winter. The stepwise multiple regression analyses identified season, daily outdoor activity, and suntan in the last 12 months as independent factors associated with vitamin D3 concentrations. Conclusion: The results suggest that low vitamin D status in recent lactating mothers may have decreased vitamin D and 25OHD concentrations in breast milk compared with the 1980s. These results are helpful for developing public health strategies to improve vitamin D status in lactating mothers and infants.


Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1714
Author(s):  
Habiba AlSafar ◽  
William B. Grant ◽  
Rafiq Hijazi ◽  
Maimunah Uddin ◽  
Nawal Alkaabi ◽  
...  

Insufficient blood levels of the neurohormone vitamin D are associated with increased risk of COVID-19 severity and mortality. Despite the global rollout of vaccinations and promising preliminary results, the focus remains on additional preventive measures to manage COVID-19. Results conflict on vitamin D’s plausible role in preventing and treating COVID-19. We examined the relation between vitamin D status and COVID-19 severity and mortality among the multiethnic population of the United Arab Emirates. Our observational study used data for 522 participants who tested positive for SARS-CoV-2 at one of the main hospitals in Abu Dhabi and Dubai. Only 464 of those patients were included for data analysis. Demographic and clinical data were retrospectively analyzed. Serum samples immediately drawn at the first hospital visit were used to measure serum 25-hydroxyvitamin D [25(OH)D] concentrations through automated electrochemiluminescence. Levels < 12 ng/mL were significantly associated with higher risk of severe COVID-19 infection and of death. Age was the only other independent risk factor, whereas comorbidities and smoking did not contribute to the outcomes upon adjustment. Sex of patients was not an important predictor for severity or death. Our study is the first conducted in the UAE to measure 25(OH)D levels in SARS-CoV-2-positive patients and confirm the association of levels < 12 ng/mL with COVID-19 severity and mortality.


Nutrients ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1801 ◽  
Author(s):  
Louise Hansen ◽  
Anne Tjønneland ◽  
Brian Køster ◽  
Christine Brot ◽  
Rikke Andersen ◽  
...  

The aim of the present study was to describe vitamin D status and seasonal variation in the general Danish population. In this study, 3092 persons aged 2 to 69 years (2565 adults, 527 children) had blood drawn twice (spring and autumn) between 2012 and 2014. A sub-sample of participants had blood samples taken monthly over a year. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured by liquid chromatography mass spectrometry, and information on supplement use was assessed from questionnaires. Seasonal variations in 25(OH)D concentrations were evaluated graphically and descriptively, and status according to age, sex, and supplement use was described. It was found that 86% of both adults and children were vitamin D-sufficient in either spring and or/autumn; however, many had a spring concentration below 50 nmol/L. A wide range of 25(OH)D concentrations were found in spring and autumn, with very low and very high values in both seasons. Among adults, women in general had higher median 25(OH)D concentrations than men. Furthermore, vitamin D supplement use was substantial and affected the median concentrations markedly, more so during spring than autumn. Seasonal variation was thus found to be substantial, and bi-seasonal measurements are vital in order to capture the sizable fluctuations in vitamin D status in this Nordic population.


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