The Association Between Vitamin D Deficiency and Diabetes in Adult African Americans and Whites: An NHANES Study.
Level 4 - case-series / case-control
Cross-sectional observational survey study using propensity score adjustment methods.
PubMed 39312091 · doi:10.1007/s40615-024-02144-4
What was done
Researchers analyzed cross-sectional data from adult participants (age ≥ 20) in the 2011–2014 National Health and Nutrition Examination Surveys (NHANES) to examine the relationship between vitamin D deficiency (VDD) and diabetes among African Americans and Whites. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were applied to control for confounding, and differences in 25-hydroxyvitamin D distributions between the two groups were evaluated.
What was found
African Americans had a higher prevalence of diabetes (12.27%, 95% CI 10.47–14.07% vs. 7.24%, 95% CI 6.35–8.13%) and VDD (65.29%, 95% CI 62.01–68.58% vs. 19.49%, 95% CI 16.53–22.45%) compared to Whites. Under PSM, VDD was associated with increased diabetes odds in Whites (OR 2.16, 95% CI 1.49–3.13) but not in African Americans (OR 0.94, 95% CI 0.70–1.27). Similarly, under IPTW, the odds ratio was 2.35 (95% CI 1.67–3.30) for Whites and 0.83 (95% CI 0.64–1.10) for African Americans. Serum 25-hydroxyvitamin D distributions differed significantly between the racial groups.
Why it matters
This study highlights that standard 25-hydroxyvitamin D cut-offs for deficiency may not hold the same clinical relevance across racial groups, suggesting that uniform diagnostic thresholds could misclassify risk in African Americans.
Limits
The study is cross-sectional, precluding determination of temporality or causality between vitamin D levels and diabetes onset. Total sample size (n) is not reported in the abstract. Standard total 25-hydroxyvitamin D assays do not account for bioavailable or free vitamin D, and residual confounding cannot be ruled out.
Cited by
- contradicts NHANES data indicate African-Americans are 30 times more likely to be vitamin D deficient than Caucasians.