Vitamin D Deficiency and Supplementation in Migraine: A Scoping Review of Clinical Efficacy, Evidence Gaps, and Research Priorities

Vitamin D deficiency is consistently associated with increased migraine burden. Supplementation shows context dependent efficacy, particularly in deficient individuals and specific subgroups. Future research should focus on mechanistic trials, global standardization of assays, and comprehensive outcome assessments. Clinically, baseline 25(OH)D testing is recommended to guide targeted supplementation strategies.