The Efficacy of Vitamin D Supplementation for Migraine: A Meta-Analysis of Randomized Controlled Studies

INTRODUCTION The efficacy of vitamin D for migraine remains controversial. We conduct a systematic review and meta-analysis to explore the influence of vitamin D versus placebo on treatment in migraine patients. METHODS We search PubMed, EMbase, Web of Science, EBSCO, and Cochrane library databases through April 2020 for randomized controlled trials assessing the effect of vitamin D versus placebo on treatment efficacy in migraine patients. This meta-analysis is performed using the random-effect model. RESULTS Five randomized controlled trials are included in the meta-analysis. Overall, compared with control group in migraine patients, vitamin D treatment is associated with substantially reduced number of headache days (standard mean difference [SMD], -0.53; 95% confidence interval [CI], -0.83 to -0.23; P = 0.0006), frequency of headache attacks (SMD, -1.09; 95% CI, -1.86 to -0.32; P = 0.006), headache severity (SMD, -0.55; 95% CI, -0.91 to -0.19; P = 0.0003), and Migraine Disability Assessment score (SMD, -0.76; 95% CI, -1.11 to -0.40; P < 0.0001). CONCLUSIONS Vitamin D treatment is effective to alleviate migraine.