Randomized trial of vitamin D supplementation for winter-related atopic dermatitis in children.

BACKGROUND: Epidemiologic and preclinical data, and a small randomized trial in Boston, suggest that vitamin D supplementation may improve winter-related atopic dermatitis (AD).

OBJECTIVE: To determine the effect of vitamin D supplementation on winter-related AD.

METHODS: We performed a randomized, double-blind, placebo-controlled trial of Mongolian children with winter-related AD (clinicaltrials.gov identifier: NCT00879424). Baseline eligibility included age 2 to 17 years, AD score 10 to 72 using the Eczema Area and Severity Index (EASI), and winter-related AD (eg, history of AD worsening during the fall-to-winter transition). Subjects were enrolled in Ulaanbaatar during winter and randomly assigned to oral cholecalciferol (1000 IU/day) versus placebo for 1 month. All children and parents received emollient and patient education about AD and basic skin care. The main outcomes were changes in EASI score and in Investigator's Global Assessment.

RESULTS: The 107 enrolled children had a mean age of 9 years (SD 5), and 59% were male. Their median age of AD onset was 3 months (interquartile range 2 months to 1 year) and mean EASI score at baseline 21 (SD 9). One-month follow-up data were available for 104 (97%) children. Compared with placebo, vitamin D supplementation for 1 month produced a clinically and statistically significant improvement in EASI score (adjusted mean change: -6.5 vs -3.3, respectively; P = .04). Moreover, change in Investigator's Global Assessment favored vitamin D over placebo (P = .03). There were no adverse effects in either group.

CONCLUSION: Vitamin D supplementation improved winter-related AD among Mongolian children, a population likely to have vitamin D deficiency in winter.