Effect of Oral Vitamin C Supplementation on Serum Uric Acid: A Meta-analysis of Randomized Controlled Trials
Juraschek SP, Miller ER, Gelber AC • Arthritis Care Res
Key Finding
Vitamin C supplementation reduced uric acid by 0.35 mg/dL (95% CI -0.66 to -0.03, P=0.032); higher baseline UA (≥4.85 mg/dL) showed 0.78 mg/dL reduction
Key Findings
- 1Vitamin C reduced uric acid by 0.35 mg/dL (95% CI −0.66 to −0.03; P=0.032)
- 2Higher baseline SUA (≥4.85 mg/dL): 0.78 mg/dL reduction
- 3Median effective dose: 500 mg/day vitamin C
- 413 RCTs with 556 participants; trial duration 7-90 days
Original title: “Effect of oral vitamin C supplementation on serum uric acid: a meta-analysis of randomized controlled trials”
Plain English Summary
Meta-analysis of 13 RCTs (556 participants) examining vitamin C supplementation effects on serum uric acid. Median dose 500 mg/day, trial duration 7-90 days.
In-Depth Analysis
Study Details
Authors: Stephen P Juraschek, Edgar R Miller III, Allan C Gelber
Institution: Johns Hopkins University
Journal: Arthritis Care Res (Hoboken), 2011 Sep; 63(9):1295-1306
PMCID: PMC3169708
Key Statistics (from original paper)
Meta-Analysis Summary
- •Trials included: 13 RCTs
- •Total participants: 556
- •Median vitamin C dose: 500 mg/day (range 200-2000 mg/day)
- •Trial duration: 7-90 days (median 30 days)
- •Baseline SUA range: 2.9-7.0 mg/dL
Primary Outcome
- •Pooled effect: −0.35 mg/dL reduction
- •95% CI: −0.66 to −0.03
- •P-value: 0.032
- •International units: −20.8 μmol/L
- •Heterogeneity: I² = 77% (P<0.01)
Subgroup Analyses
| Subgroup | Effect (mg/dL) |
|---|---|
| Higher baseline SUA (≥4.85 mg/dL) | −0.78 |
| Placebo-controlled trials | −0.59 |
| Vitamin C alone (≥500 mg) | −0.59 |
Conclusion
Modest but statistically significant SUA reduction with vitamin C supplementation, particularly in individuals with elevated baseline uric acid.
Source: PMC full text (PMC3169708)
Paradigm Relevance
How this study applies to different clinical perspectives:
Standard Medical
RelevantConventional clinical guidelines used by most doctors
Why it matters:
Supports vitamin C as adjunct to uric acid management. Effect size modest — not a substitute for urate-lowering drugs when indicated.
Research Consensus
RelevantCurrent scientific understanding, often ahead of guidelines
Why it matters:
Provides mechanistic evidence for vitamin C effect on uric acid excretion. May be more effective in those with higher baseline levels.
Metabolic Optimization
RelevantProactive targets for optimal health, not just disease absence
Why it matters:
Low-risk intervention for hyperuricemia prevention. 500-1000 mg daily reasonable adjunct. Combines well with other lifestyle strategies.
Study Details
- Type
- Meta-Analysis
- Methodology
- Meta-analysis of 13 RCTs. N = 556 total participants. Median vitamin C dose 500 mg/day. Trial duration 7-90 days (median 30 days).
Evidence Quality
Grade A - Meta-analysis. PMC3169708. Johns Hopkins University.
Topic
Calculate & Evaluate on Metabolicum
Original Source
DOI (Digital Object Identifier) is a permanent link to this publication. Unlike website URLs that can change, a DOI always resolves to the correct source.
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