Vitamin D status and acute lower respiratory infection in early childhood in Sylhet, Bangladesh

Aim: Acute lower respiratory tract infection (ALRI) is the most important global cause of childhood death. Micronutrient deficiencies may increase the risk of ALRI. A case-control study was conducted to assess the association between vitamin D status and ALRI in rural Bangladesh. Methods: Children aged 1-18 months hospitalized with ALRI (cases) were individually matched to controls on age, sex, and village (N = 25 pairs). The mean serum 25-hydroxyvitamin D concentration [25(OH)D] in cases and controls was compared using paired t-test. The unadjusted and adjusted odds of ALRI were assessed by multivariate conditional logistic regression. Results: Mean [25(OH)D] was significantly lower among ALRI cases than controls (29.1 nmol/L vs. 39.1 nmol/L; p = 0.015). The unadjusted odds of ALRI was halved for each 10 nmol/L increase in [25(OH)D] (OR 0.53, 95% CI 0.30-0.96). Adjustment for confounders increased the magnitude of the association. Conclusion: Vitamin D status was associated with early childhood ALRI in a matched case-control study in rural Bangladesh. Randomized trials may establish whether interventions to improve vitamin D status can reduce the burden of ALRI in early childhood.