Research synthesisModerate evidenceSmall effect8 studies · 6 beneficial · 2 neutral · 0 harmful
Across 8 studies, 6 reported beneficial effects of vitamin C on reducing pain, with effect sizes ranging from small to moderate. The median study duration was 60 days across the 3 studies reporting duration, suggesting effects may require several weeks of supplementation. The evidence is strongest for postoperative pain (e.g., dental surgery and hip arthroplasty), with some studies also showing benefit in fibromyalgia and carpal tunnel syndrome.
- Studied populations: patients undergoing surgery (dental extractions, total hip or knee arthroplasty), adults with fibromyalgia, patients with carpal tunnel syndrome
Caveats: Available evidence is overwhelmingly positive (75% of studies show benefit) — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). Doses varied considerably across studies and were often not specified, making it difficult to identify a consistent effective dose. The highest-quality study (meta-analysis, n=852) found no significant effect, contrasting with smaller positive RCTs, suggesting possible exaggeration of benefit in smaller trials.
Generated Jul 10, 2026