Prevalence and risk factors of vitamin D insufficiency and deficiency among 6-24-month-old underweight and normal-weight children living in an urban slum of Bangladesh

Objective: We quantified the prevalence of vitamin D status in 6-24-month-old underweight and normal-weight children and identified the socio-economic and dietary predictors for status. Design: Cross-sectional, baseline data from a nutritional intervention study were analysed. Multinomial logistic regression was used to estimate the odds of being vitamin D deficient or insufficient with the reference being vitamin D sufficient. Setting: Urban slum area of Mirpur field site, Dhaka, Bangladesh. Subjects: Underweight (weight-for-age Z-score <-2.00) and normal-weight (weight-for-age Z-score >=-1.00) children aged 6-24 months. Results: Among 468 underweight children, 23.1% were sufficient, 42.3% insufficient, 31.2% deficient and 3.4% severely vitamin D deficient. Among 445 normal-weight children, 14.8% were sufficient, 39.6% insufficient and 40.0% deficient and 5.6% severely deficient. With adjusted multinominal regression analysis, risk factors (OR (95% CI)) for vitamin D deficiency in underweight children were: older age group (18-24 months old; 2.9 (1.5-5.7)); measurement of vitamin D status during winter (3.0 (1.4-6.4)) and spring (6.9 (3.0-16.1)); and maternal education (>= 6 years of institutional education; 2.2 (1.0-4.9)). In normal-weight children, older age group (3.6 (1.2-10.6)) and living in the richest quintile (3.7 (1.1-12.5)) were found to be significantly associated with vitamin D insufficiency. Conclusions: The study demonstrates a significant burden of vitamin D insufficiency and deficiency in both underweight and normal-weight children <2 years of age from an urban slum of Bangladesh. Identification of risk factors may help in mitigating the important burden in such children.