Does Vitamin D Supplementation Reduce Asthma Exacerbations in Children?

Observational studies suggest that low serum 25-hydroxyvitamin D levels may be a risk factor for asthma exacerbations, but studies examining vitamin D replacement in patients with asthma have been inconclusive.

In this multicenter trial, 192 children aged 6 to 16 years with a history of a severe asthma exacerbation in the previous year and serum vitamin D levels between 10 and 30 ng/mL were randomized to 48 weeks of daily vitamin D₃ at a dose of 4000 IU or placebo. In addition, all children received inhaled fluticasone. The study was stopped early due to futility. Time to a severe exacerbation (the primary outcome) did not differ significantly between the vitamin D₃ and placebo groups (mean, 240 and 253 days), even though 87% of the vitamin …