Vitamin D Status and Efficacy of Vitamin D Supplementation in Atopic Dermatitis: A Systematic Review and Meta-Analysis

Recent literature has highlighted the possible role of vitamin D in atopic dermatitis (AD), and that vitamin D supplementation might help to treat AD. This study determined the relationship between vitamin D level and AD, and assessed the efficacy of vitamin D supplementation. We searched the MEDLINE, EMBASE, and Cochrane databases up to May 2015. Observational studies and randomized controlled trials were included based on the available data on the serum 25-hydroxyvitamin D (25(OH) D) level and quantified data available for severity assessed using the Scoring Atopic Dermatitis (SCORAD) index or Eczema Area and Severity Index (EASI) score. Compared with healthy controls, the serum 25(OH) D level was lower in the AD patients of all ages (standardized mean difference = 2.03 ng/mL; 95% confidence interval (CI) = 2.52 to 0.78), and predominantly in the pediatric AD patients (standardized mean difference = 3.03 ng/mL; 95% CI = 4.76 to 1.29). In addition, the SCORAD index and EASI score decreased after vitamin D supplementation (standardized mean difference = 5.85; 95% CI = 7.66 to 4.05). This meta-analysis showed that serum vitamin D level was lower in the AD patients and vitamin D supplementation could be a new therapeutic option for AD.