Prevalence and correlates of vitamin D deficiency in a tropical setting: results from a nationally representative survey.

BACKGROUND

The prevalence of vitamin D deficiency (VDD) may be high in countries with abundant sun exposure year-round, but nationally representative data are lacking.

OBJECTIVE

We examined the prevalence and distribution of VDD by individual and environmental characteristics in a nationally representative sample of Colombian children, pregnant women, and adult nonpregnant women.

METHODS

Using the 2015 Colombian National Nutrition Survey, we defined VDD and low vitamin D (LVD) as serum 25-hydroxyvitamin D [25(OH)D] <30 nmol/L and <50 nmol/L, respectively, in 31,841 children aged 1 to <18 y, 1262 pregnant women, and 7170 nonpregnant women aged 18-49 y. Within each group, we compared VDD and LVD prevalence by levels of sociodemographic, anthropometric, and geographic factors using adjusted prevalence ratios with 95% CIs from multivariable Poisson regression.

RESULTS

The mean ± SE 25(OH)D was 65.1 ± 0.4 nmol/L. The prevalence ± SE of VDD and LVD was 3.1% ± 0.3% and 23.9% ± 0.8%, respectively. Pregnant women had the highest VDD prevalence at 6.7% ± 1.5%, whereas toddlers had the highest prevalence of LVD at 42.5% ± 1.8%. Altitude was one of the strongest correlates of VDD and LVD, with every 100 m above sea level related to a 4% increase in LVD prevalence (P <0.0001). Among children, VDD was positively associated with BMI-for-age Z >1 and maternal education. Among pregnant women, VDD was positively related to education. Among adult nonpregnant women, VDD was associated with BMI and household wealth.

CONCLUSION

The prevalence of VDD and LVD in Colombian women and children is nonnegligible; some age groups are disproportionately affected. Altitude was a strong predictor of vitamin D status in this tropical setting. VDD was positively related to indicators of higher socioeconomic status.