Vitamin D supplementation modulates the immune system and improves atopic dermatitis in children.

BACKGROUND Vitamin D seems to influence the evolution of atopic dermatitis (AD) in children. METHODS We tested the vitamin D serum levels of 39 children with AD (AD group t0) and of 20 nonallergic healthy controls (C group). AD severity was evaluated using the AD scoring system (SCORAD index). Cytokine serum levels (IL-2, IL-4, IL-6, IFN-γ, TNF-α) and atopy biomarkers were also measured. The patients were then treated with vitamin D oral supplementation of 1,000 IU/day (25 mg/day) for 3 months. We then reevaluated the vitamin D serum levels, AD severity and cytokine serum levels in all of the treated children (AD group t1). RESULTS The cross-sectional analysis on patients affected by AD (AD group t0) showed that the initial levels of all the tested cytokines except for TNF-α were higher than those of the healthy control group (C group), falling outside the normal range. After 3 months of supplementation the patients had significantly increased vitamin D levels (from 22.97 ± 8.03 to 29.41 ± 10.73 ng/ml; p = 0.01). A concomitant significant reduction of both the SCORAD index (46.13 ± 15.68 at the first visit vs. 22.57 ± 15.28 at the second visit; p < 0.001) and of all the altered cytokines (IL-2, IL-4, IL-6, IFN-γ) was also found. CONCLUSIONS This study showed vitamin D supplementation to be an effective treatment in reducing AD severity in children through normalization of the Th1 and Th2 interleukin serum pattern.