RESUMO
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.