Prevalence and correlates of vitamin D deficiency in US adults.
Level 4 - case-series / case-control
Cross-sectional analysis of national survey data
PubMed 21310306 · doi:10.1016/j.nutres.2010.12.001
What was done
Researchers analyzed serum 25-hydroxyvitamin D levels from 4,495 adult participants in the 2005–2006 National Health and Nutrition Examination Survey (NHANES). Vitamin D deficiency was defined as a serum concentration of 20 ng/mL (50 nmol/L) or less. Univariate and multivariate regression analyses were performed to identify demographic, lifestyle, and cardiometabolic correlates of deficiency.
What was found
The overall prevalence of vitamin D deficiency among US adults was 41.6%. Prevalence was highest among Black participants (82.1%) and Hispanic participants (69.2%). In multivariate analyses, independent predictors of deficiency (all P < .05) were non-white race, lack of a college education, obesity, low high-density lipoprotein (HDL) cholesterol, self-reported poor health status, and lack of daily milk consumption.
Why it matters
This study documents widespread vitamin D deficiency in the US adult population, identifying severe racial disparities and associations with key cardiometabolic risk factors.
Limits
The cross-sectional design precludes causal inferences regarding the direction of associations between vitamin D deficiency and health status or metabolic markers. Findings rely on a single 2-year survey cycle and a single threshold definition (≤20 ng/mL), without assessing clinical endpoints or seasonal variation in sun exposure.
Cited by
- supports NHANES data show that approximately 70% of the US population is vitamin D insufficient and 30% is vitamin D deficient.