Efficacy and safety of weekly vitamin D in patients with fibromyalgia: 12-week, double-blind, randomized, controlled placebo trial.

Introduction: FM is a chronic musculoskeletal disorder characterized by the presence of generalized pain. There are contradictory results regarding the prevalence and supplementation effect of vitamin D deficiency on FM patients. We aim to determine the safety and efficacy of a 12-week vitamin D supplementation on FM patients.