Effect of vitamin D supplementation on total and allergen-specific IgE in children with asthma and low vitamin D levels

Background: Observational studies have yielded inconsistent findings for the relation between vitamin D level and total IgE or allergic sensitization. Objective: To determine whether vitamin D supplementation reduces levels of total IgE and IgE to each of 2 common indoor allergens in children with asthma and low vitamin D levels. Methods: Total IgE, IgE to Dermatophagoides pteronyssinus, and IgE to Blattella germanica were measured at the randomization and exit visits for 174 participants in the Vitamin D Kids Asthma Study, a multicenter, double-blind, randomized placebo-controlled trial of vitamin D₃ supplementation (4000 IU/d) to prevent severe exacerbations in children with persistent asthma and vitamin D levels less than 30 ng/mL. Multivariable linear regression was used for the analysis of the effect of vitamin D supplementation on change in each IgE measure. Results: Participants were followed for an average of 316 days. At the exit visit, more subjects in the vitamin D arm achieved a vitamin D level equal to or more than 30 ng/mL compared with those in the placebo arm (87% vs 30%; P <.001). In a multivariable analysis, vitamin D₃ supplementation had no significant effect on change in total IgE, IgE to Dermatophagoides pteronyssinus, or IgE to Blattella germanica between the exit and randomization visits (eg, for log₁₀ total IgE, β = 0.007; 95% CI, −0.061 to 0.074; P =.85). Conclusions: Vitamin D supplementation, compared with placebo, has no significant effect on serum levels of total IgE, IgE to dust mite, or IgE to cockroach in children with asthma and low vitamin D levels.