Efficacy of vitamin D supplementation on the severity of atopic dermatitis in children: A systematic review and meta-analysis [version 1; peer review: 1 approved, 1 approved with reservations]

Background: Atopic Dermatitis (AD) is a common dermatosis in children, that includes skin architecture defects, immune dysregulation, and changes of skin flora. Several new drugs have been found to reduce the severity of AD. Vitamin D is one of the new therapies that is still controversial. The purpose of this research is to conclude the efficacy of vitamin D on atopic dermatitis severity in children aged 0-18 years old. Methods: A systematic search was conducted on the PubMed, Cochrane, ProQuest, Google Scholar, Clinical Trial website, and university repositories including studies published from January 2010 through October 2020. We compared populations, intervention, study design, and outcomes. Statistical analysis was done with Review Manager 5.4.1. Results: Eight articles met eligibility and inclusion criteria, four articles provided complete data and were analysed. Not all studies demonstrated the efficacy of vitamin D but a meta-analysis of four studies of vitamin D supplementation vs placebo found a mean difference of -0.93 (95%CI -1.76, to -0.11, p