Serum 25-hydroxyvitamin D status of the US population: 1988–1994 compared to 2000–2004

National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, MD 20782, USA.
American Journal of Clinical Nutrition (Impact Factor: 6.77). 01/2009; 88(6):1519-27. DOI: 10.3945/ajcn.2008.26182
Source: PubMed


Changes in serum 25-hydroxyvitamin D [25(OH)D] concentrations in the US population have not been described.
We used data from the National Health and Nutrition Examination Surveys (NHANES) to compare serum 25(OH)D concentrations in the US population in 2000-2004 with those in 1988-1994 and to identify contributing factors.
Serum 25(OH)D was measured with a radioimmunoassay kit in 20 289 participants in NHANES 2000-2004 and in 18 158 participants in NHANES III (1988-1994). Body mass index (BMI) was calculated from measured height and weight. Milk intake and sun protection were assessed by questionnaire. Assay differences were assessed by re-analyzing 150 stored serum specimens from NHANES III with the current assay.
Age-adjusted mean serum 25(OH)D concentrations were 5-20 nmol/L lower in NHANES 2000-2004 than in NHANES III. After adjustment for assay shifts, age-adjusted means in NHANES 2000-2004 remained significantly lower (by 5-9 nmol/L) in most males, but not in most females. In a study subsample, adjustment for the confounding effects of assay differences changed mean serum 25(OH)D concentrations by approximately 10 nmol/L, and adjustment for changes in the factors likely related to real changes in vitamin D status (ie, BMI, milk intake, and sun protection) changed mean serum 25(OH)D concentrations by 1-1.6 nmol/L.
Overall, mean serum 25(OH)D was lower in 2000-2004 than 1988-1994. Assay changes unrelated to changes in vitamin D status accounted for much of the difference in most population groups. In an adult subgroup, combined changes in BMI, milk intake, and sun protection appeared to contribute to a real decline in vitamin D status.

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    • "Differences in serum vitamin D [25(OH)D] concentration among racial/ethnic groups are suspected to be one of the sources of health disparities (Grant and Peiris 2010; Harris 2011). Numerous studies demonstrated that AAs have significantly lower serum 25(OH)D levels than EAs (Benjamin et al. 2009; Chan et al. 2010; Ginde et al. 2009; Harris et al. 2000; Looker et al. 2008; Murphy et al. 2012; Nesby-O’Dell et al. 2002; Shea et al. 2011; Tseng et al. 2009). Vitamin D deficiency is common even among AAs who live in sunlight intense southern and southwestern states or who have higher dietary vitamin D intake than the longstanding recommended daily allowance (≥400 IU/day) (Egan et al. 2008; Jacobs et al. 2008; Tseng et al. 2009). "
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    ABSTRACT: Vitamin D deficiency is more common among African Americans (AAs) than among European Americans (EAs), and epidemiologic evidence links vitamin D status to many health outcomes. Two genome-wide association studies (GWAS) in European populations identified vitamin D pathway gene single-nucleotide polymorphisms (SNPs) associated with serum vitamin D [25(OH)D] levels, but a few of these SNPs have been replicated in AAs. Here, we investigated the associations of 39 SNPs in vitamin D pathway genes, including 19 GWAS-identified SNPs, with serum 25(OH)D concentrations in 652 AAs and 405 EAs. Linear and logistic regression analyses were performed adjusting for relevant environmental and biological factors. The pattern of SNP associations was distinct between AAs and EAs. In AAs, six GWAS-identified SNPs in GC, CYP2R1, and DHCR7/NADSYN1 were replicated, while nine GWAS SNPs in GC and CYP2R1 were replicated in EAs. A CYP2R1 SNP, rs12794714, exhibited the strongest signal of association in AAs. In EAs, however, a different CYP2R1 SNP, rs1993116, was the most strongly associated. Our models, which take into account genetic and environmental variables, accounted for 20 and 28 % of the variance in serum vitamin D levels in AAs and EAs, respectively. Electronic supplementary material The online version of this article (doi:10.1007/s00439-014-1472-y) contains supplementary material, which is available to authorized users.
    Full-text · Article · Aug 2014 · Human Genetics
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    • "Epidemiological studies of the association of vitamin D with disease are complicated because circulating vitamin D levels are determined by a variety of factors, including ultraviolet radiation exposure, skin sensitivity to sun exposure, and diet [19-22]. Most investigations examining vitamin D and breast cancer risk have been conducted in whites, however; and circulating levels of 25(OH)D, the most reliable indicator of vitamin D status, are known to differ substantially between race/ethnic groups with varying diets and ability to synthesize vitamin D in the skin [19,21,23]. "
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    ABSTRACT: Higher sunlight exposure is correlated with lower incidence of breast cancer in ecological studies, but findings from prospective studies regarding the association of circulating levels of vitamin D with the risk of breast cancer have been null. The objective of this study was to examine the relation between plasma levels of vitamin D and the risk of postmenopausal breast cancer. We conducted a nested case-control study within the Multiethnic Cohort Study of five race/ethnic groups (white, African-American, Native Hawaiian, Japanese, and Latino) from Hawaii and Los Angeles between 2001 and 2006. Pre-diagnostic plasma levels of 25-hydroxyvitamin D2 [25(OH)D2], 25-hydroxyvitamin D3 [25(OH)D3] and 25(OH)D (sum of 25(OH)D2 and 25(OH)D3) were examined among 707 postmenopausal breast cancer cases and matched controls. Using conditional logistic regression models, 20 ng/mL increases of plasma 25(OH)D3 (odds ratio (OR) 0.28; 95% confidence interval (CI) 0.14-0.56) and 25(OH)D (OR 0.43; 95% CI 0.23-0.80) were inversely associated with breast cancer risk among white women, but not among women in other race/ethnic groups. Using two-segmented, piecewise-linear logistic regression models, the change-points of the ORs, either for 25(OH)D3 or for 25(OH)D, were detected as 20 ng/mL among whites. Circulating 25(OH)D3 and 25(OH)D were associated with a reduced risk of postmenopausal breast cancer among whites, but not in other ethnic groups, who reside in low latitude regions.
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    • "Moreover, vitamin D is a modulator of the innate and adaptive immune system and prospective observational studies suggest that vitamin D supplements in infancy and early childhood may decrease the incidence of chronic diseases such as type 1 diabetes mellitus [1,2]. Current data within the literature demonstrates a high prevalence of vitamin D insufficiency not only in adult and in children, but also in pregnant women and in their neonates [3-5]. Risk factors for vitamin D deficiency and rickets in early life include breast-feeding without vitamin D supplementation, dark skin pigmentation, season, latitude and maternal vitamin D deficiency [1]. "
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    ABSTRACT: Background A deficiency in vitamin D (25OHD) is common throughout the world in both adults and children, being related to skin pigmentation, sun exposure, dietary intake and obesity. Limited data are available for the neonatal age. The aim of the study is to understand the differences in 25OHD levels with respect to skin colour and ethnicity in newborns. Methods We randomly enrolled 62 neonates, born at term and appropriate for gestational age. Thirty two were born from Italian mothers with fair skin (FS) and 30 from non-Caucasian mothers (North African, African, Asian and Latin American): 10 with light olive/light brown (LOB) and 20 with medium brown/black skin (MBB). Vitamin D was measured in the cord blood at birth and in neonatal serum during metabolic screening. Results 25OHD levels were (mean ± SD) 21.4 ± 11 ng/ml in cord blood and 14.9 ± 7 ng/ml in serum after birth. 25OHD values were higher in cord blood (p < 0.01) and neonatal serum (p < 0.001) in subjects supplemented with Vitamin D. Newborn FS showed higher vitamin D levels in cord blood when compared to LOB and MBB (p < 0.01), and higher levels in neonatal serum when compared to LOB (p < 0.01). In cord blood, 25OHD levels were higher in Italian newborns than in North African (p < 0.004) and African (p < 0.01). In neonatal serum, 25OHD levels were higher in Italian infants only when compared with North African infants (p < 0.03). Conclusions The present study shows a high prevalence of vitamin D insufficiency and deficiency in newborns with significant differences observed to be due to ethnicity, skin colour and maternal supplementation during the pregnancy.
    Full-text · Article · Jun 2013 · Italian Journal of Pediatrics
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