From the Guidelines
Vitamin C supplementation may be beneficial in reducing serum urate levels in patients with gout, but its effect is relatively small compared to standard treatments like allopurinol or febuxostat. The relationship between Vitamin C (Ascorbic Acid) and Gout (Hyperuricemia) is supported by low-quality evidence from a systematic review of 13 trials, which showed that vitamin C supplementation reduced serum urate levels by −20.8 µmol/L [−0.35 mg/dL] [95% CI, −39.3 to −1.8 µmol/L {−0.66 to −0.03 mg/dL}] 1.
Key Points to Consider
- Vitamin C may help reduce gout symptoms and lower uric acid levels in some people, but it's not a primary treatment for gout.
- For those with gout, taking 500-1,500 mg of vitamin C daily as a supplement might modestly reduce uric acid levels by increasing its excretion through the kidneys.
- The effect of vitamin C on uric acid levels is relatively small compared to prescription medications like allopurinol or febuxostat, which remain the standard treatments for chronic gout.
- If considering vitamin C for gout management, it's best used as a complementary approach alongside proper medical treatment, dietary changes (reducing purine-rich foods like red meat and seafood), limiting alcohol consumption, and maintaining a healthy weight.
- Some people with gout should be cautious with vitamin C supplements, particularly those with kidney disease or a history of kidney stones, as high doses may worsen these conditions.
Mechanism of Action
The connection between vitamin C and gout relates to its mild uricosuric effect, meaning it helps the body eliminate uric acid, the substance that forms painful crystals in joints during gout attacks. However, high-quality evidence from 4 RCTs showed that urate-lowering therapy (allopurinol and febuxostat) reduces serum urate levels, and moderate-quality evidence suggests that longer-term urate-lowering therapy (>1 year) reduces gout flares 1.
Clinical Implications
In clinical practice, vitamin C supplementation may be considered as an adjunctive treatment for gout, but it should not replace standard treatments. Patients with gout should be advised to maintain a healthy lifestyle, including a balanced diet, regular exercise, and limited alcohol consumption, in addition to taking their prescribed medications as directed. Further research is needed to fully understand the relationship between vitamin C and gout, but current evidence suggests that it may be a useful complementary therapy for some patients 1.
From the Research
Relationship Between Vitamin C and Gout
- The relationship between Vitamin C (Ascorbic Acid) and Gout (Hyperuricemia) is complex, with some studies suggesting a potential link between Vitamin C intake and reduced serum uric acid levels 2.
- However, a pilot randomized controlled trial found that supplemental vitamin C had a clinically insignificant effect on serum urate levels in patients with gout 3.
- Epidemiological studies have reported a significant correlation between high vitamin C intake and lower serum uric acid levels, but the results of observational and interventional studies are not conclusive 2.
Effects of Vitamin C on Serum Urate Levels
- A study found that a modest dosage of vitamin C (500 mg/day) for 8 weeks had no clinically significant urate-lowering effects in patients with gout, despite an increase in plasma ascorbate levels 3.
- The reduction in serum urate levels was significantly less in patients receiving vitamin C compared to those who started or increased the dose of allopurinol 3.
Gout Treatment and Management
- Gout treatment typically involves pharmacotherapies such as colchicine, NSAIDs, and oral or intramuscular corticosteroids for acute flares, and urate-lowering therapies like allopurinol and febuxostat to prevent flares 4, 5.
- Vitamin C is not a standard treatment for gout, and its role in prophylaxis and treatment is still being researched 2.
Limitations and Future Research
- More research is needed to fully understand the relationship between Vitamin C and Gout, including large-scale clinical trials to determine the effectiveness of Vitamin C supplementation in preventing and treating gout 2.
- The current evidence is limited, and the results of available studies are not conclusive, highlighting the need for further investigation 3, 2.