Venkatesan N, et al. Curr Rheumatol Rev. 2022 Mar 7. PMID: 35255799.
....We conducted a systematic literature review to examine the efficacy of vitamin D supplementation in improving the clinical status of the patients and alleviating the symptoms of fibromyalgia....
Results: 2651 studies were retrieved, with 12 studies fulfilling the inclusion criteria. 11 out of these 12 studies were of high quality and showed low risk of bias. 11 of these also demonstrated definitive improvement in clinical status and various outcome measures following supplementation with Vitamin D.
Conclusions: Our study emphasizes an association between supplementation of vitamin D and improvement of the clinical condition of fibromyalgia through a systematic review of high-quality studies....