Supplements
vitamin D treats fibromyalgia
📅 Last reviewed: 2026-07-15 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: All trials, pooled (Meta-analysis)
How the studies fall
What the evidence shows
Vitamin D supplementation reduces fibromyalgia pain, especially in deficient patients.
The evidence (6)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Ilari S, et al. 2025 · Nutrients | meta-analysis | supports | low | Vitamin D supplementation reduces FM pain vs control, especially in deficient patients. |
| Lozano-Plata LI, et al. 2021 · Clin Rheumatol | RCT | mixed | moderate | RCT (12-wk weekly vit D in FM): modest/null-leaning effect on pain — mixed result. |
| Wepner F, et al. 2014 · Pain | RCT | supports | moderate | RCT (n=30): vitamin D optimization (target 32-48 ng/mL) significantly reduced VAS pain vs placebo. |
| Ersoy S, Kesiktas FN, Sirin B, Bugdayci D, Paker N 2024 · Ir J Med Sci | observational | mixed | low | DESIGN MISMATCH: titled 'the effect of vitamin D treatment' but the methods describe a CROSS-SECTIONAL study of 180 female fibromyalgia patients - not an interventional trial. Graded observational/low on that basis; cannot support a treatment-effect claim. |
| mirzaei-2018-vitd 2018 | RCT | supports | moderate | RCT: vitamin D vs control improved quality-of-life outcomes in FM. ↩ SUPERSEDED — pooled in the review above, counted once |
| Qu K, Li MX, Zhou YL, Yu P, Dong M 2022 · Expert Rev Clin Pharmacol | meta-analysis | mixed | moderate | Independent MA of 5 RCTs (n=315): Fibromyalgia Impact Questionnaire improved (WMD -7.82, 95% CI -12.05 to -3.59, p<0.001) BUT pain VAS showed NO significant difference (WMD -0.60, 95% CI -1.38 to 0.17, p>0.05). Benefit on the function questionnaire, not on pain itself - graded mixed for that split. |
Disagree, or know a study we missed?
We grade by evidence, not opinions. The way to weigh in is to point us to a study we haven't cited (check the evidence table above first), or to flag a problem with one we have. Every submission is reviewed; if it holds up, the grade updates and shows in Science Changes Its Mind.
Opens a short form. You'll sign in with Google so submissions are tied to a real account — we don't display your identity, and we only accept a link we can verify (PubMed, DOI, ClinicalTrials.gov).
Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.