Published Online: October, 2014
Over the past decade, several studies have suggested that vitamin D supplementation might improve atopic dermatitis (AD). In 2008, a small randomized trial in Boston (with only 11 participants) supported the potential benefit of vitamin D supplementation in children with winter-related AD. In the October theme issue of The Journal of Allergy and Clinical Immunology (JACI), Dr. Carlos Camargo and colleagues report the results of a much larger, more definitive, randomized controlled trial designed to answer the question: Does vitamin D supplementation help children with winter-related AD?
This study was optimally designed for drawing conclusions about cause-and-effect; it was a randomized, double-blind, placebo-controlled trial. The participants were 107 Mongolian children with winter-related AD (e.g., they had a history of AD worsening during the fall-to-winter transition). Children were enrolled during winter and randomly assigned to oral vitamin D supplement (1000 IU daily) or placebo for one month. The main outcomes were change in the Eczema Area and Severity Index (EASI), a validated AD outcome, and the Investigator’s Global Assessment.
The two groups (vitamin D and placebo) were similar at baseline, with an average age of 9 years. The children had a median age of AD onset of 3 months. One-month follow-up data were available for 104 (97%) children. Compared to placebo, vitamin D supplementation produced a clinically and statistically significant improvement in EASI score. Moreover, the change in the Investigator’s Global Assessment also favored vitamin D over placebo. There were no adverse effects in either group.
Vitamin D supplementation improved winter-related AD among Mongolian children, a population that is likely to have vitamin D deficiency in winter. The results are consistent with the earlier randomized controlled trial in Boston. Together, along with numerous biologically-plausible mechanisms, the trials provide strong support for the benefit of vitamin D supplementation in children with winter-related AD.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.