Effectiveness of oral vitamin D supplementation in lessening disease severity among patients with psoriasis: A systematic review and meta-analysis of randomized controlled trials.

Abstract

Many treatment modalities have been used to manage psoriasis; however, there is, to our knowledge, no pooled estimate for the effectiveness of oral vitamin D supplements in patients with psoriasis. Hence, the aim of the present study was to systematically review and meta-analyze the efficacy of oral vitamin D supplementation in lessening disease severity of patients with psoriasis. A systematic literature review was performed on the electronic databases PubMed, Embase, and Cochrane Central and the gray literature for retrieving randomized controlled trials comparing oral vitamin D supplementation with placebo. The primary outcome was the change of Psoriasis Area and Severity Index (PASI) score. We used the random effects model for synthesizing the evidence. Of the total 5018 search results, 4 studies were included in the qualitative and 3 studies in quantitative analysis. Vitamin D supplementation was effective in ameliorating the PASI score after 6 mo of intervention (mean difference [MD]=-0.92, 95% confidence interval [CI]=-1.72 to -0.11). However, after the Hartung-Knapp adjustment, the results became non-significant (MD=-0.92, 95% CI=-2.21 to 0.38). A favorable effect of oral vitamin D supplementation in patients with psoriasis could not be verified. More randomized controlled trials with larger sample sizes are needed to produce robust results.