Vitamin D deficiency and insufficiency among US adults: prevalence, predictors and clinical implications.
Level 4 - case-series / case-control
Cross-sectional survey analysis of nationally representative data (NHANES)
PubMed 29644951 · doi:10.1017/S0007114518000491
What was done
Serum 25-hydroxyvitamin D [25(OH)D] measurements were analyzed in 26,010 adults aged 18 years and older from the National Health and Nutrition Examination Survey (NHANES) 2001–2010. Vitamin D deficiency (VDD) was defined as 25(OH)D <50 nmol/l and insufficiency (VDI) as 50 to <75 nmol/l using Endocrine Society guidelines. Weighted multinomial log-binomial regression was used to estimate adjusted prevalence ratios for sociodemographic, lifestyle, and dietary predictors.
What was found
The prevalences of VDD and VDI in 2001–2010 were 28.9% and 41.4%, respectively. Adults who were Black, less educated, poor, obese, current smokers, physically inactive, and infrequent milk consumers had higher VDD prevalence. After adjustment for predictors, obese adults had 3.09 times higher prevalence of VDD and 1.80 times higher prevalence of VDI than non-obese adults. Physically inactive adults had 2.00 and 1.36 times higher prevalence of VDD and VDI, respectively, compared to active peers. Rare milk consumers had 2.44 and 1.25 times higher prevalence of VDD and VDI compared to frequent consumers. Current alcohol drinkers had a 38% lower prevalence of VDD than non-drinkers.
Why it matters
This study provides representative national benchmarks showing that over 70% of US adults had suboptimal vitamin D status between 2001 and 2010, identifying key demographic and lifestyle risk groups for clinical monitoring and intervention.
Limits
The cross-sectional design cannot establish causality between the identified lifestyle predictors and vitamin D levels. The abstract does not report confidence intervals, exact p-values, seasonal variation adjustments, supplement use, or sun exposure data.
Cited by
- supports More than half of the United States population has insufficient vitamin D levels due to spending the majority of time indoors.