Efficacy of vitamin D supplementation in asthmatic children with vitamin D deficiency: A randomized controlled trial (ESDAC trial).

Abstract

Vitamin D supplementations for asthma control had shown inconsistent results. We aimed to study efficacy and safety of vitamin D supplementation in asthmatic children who were vitamin D deficient. This double-blind, randomized controlled trial enrolled asthmatic children of 4-12years of age who had 25-hydroxyvitamin D [25(OH)D] levels <20ng/mL. The participants were randomized to receive either vitamin D orally 1000IU/d for 9months or similar-looking placebo. The primary outcomes were the proportion of children having the Childhood Asthma Control Test (CACT) score of ≥20 at the end of the treatment and adverse effects. The trial included 250 children (125 in each group) with a mean age of 8.1±2.3years and 180 boys. The baseline parameters were similar between the groups, including CACT score (21.7±4.2 vs 21.9±3.6, vitamin D vs placebo). At the end of the study, the proportion of asthmatic children who had CACT score≥20 was similar between vitamin D and placebo group (93.6% vs 92.0%, P=.625). The number of exacerbations of asthma and side effect profile was also identical between the groups. 25(OH)D levels increased significantly in the vitamin D group (18.06±7.11 vs 12.03±5.98ng/mL, P<.001). The results did not change when we did subgroup analysis for children with baseline CACT score<20 and 25(OH)D levels at the end of the study ≥20ng/mL. Vitamin D supplementation in asthmatic children with vitamin D deficiency did not improve control of asthma.