From the Guidelines
Vitamin C supplementation has been shown to reduce serum urate levels, with a mean reduction of −20.8 µmol/L [−0.35 mg/dL] [95% CI, −39.3 to −1.8 µmol/L {−0.66 to −0.03 mg/dL}] according to low-quality evidence from a systematic review of 13 trials 1. When considering the relationship between Vitamin C and uric acid levels, several key points emerge:
- The reduction in serum urate levels associated with Vitamin C supplementation is modest but potentially beneficial for individuals with gout or hyperuricemia.
- The evidence supporting this relationship is based on a systematic review of 13 trials, which showed significant heterogeneity but overall suggested a positive effect of Vitamin C on uric acid levels 1.
- It is essential to note that while Vitamin C may help reduce uric acid levels, it should be used as a complementary approach rather than a replacement for prescribed medications like allopurinol or febuxostat in individuals with gout.
- The optimal dosage of Vitamin C for reducing uric acid levels is not well established, but typical supplemental doses range from 500-1000mg daily.
- Individuals considering Vitamin C supplementation should be aware of potential interactions and side effects, particularly those with kidney stones or digestive issues, and consult their doctor before starting supplementation.
From the Research
Relationship Between Vitamin C and Uric Acid Levels
- The relationship between Vitamin C and uric acid levels has been studied in several research papers 2.
- A randomized controlled trial found that vitamin C supplementation (500 mg/day) for 2 months significantly reduced serum uric acid levels in nonsmokers 2.
- The study found that serum uric acid levels were reduced by a mean of -0.5 mg/dl in the vitamin C group, compared to a mean change of 0.09 mg/dl in the placebo group 2.
- The reduction in serum uric acid levels was evident in subgroups defined by age, sex, race, body mass index, chronic illness, diuretic use, and quartiles of baseline serum ascorbic acid levels 2.
- Vitamin C supplementation also increased the estimated glomerular filtration rate, suggesting that it may be beneficial in the prevention and management of gout and other urate-related diseases 2.
Comparison with Other Urate-Lowering Therapies
- Other studies have compared the effects of febuxostat and allopurinol on uric acid reduction and renal outcomes in patients with chronic kidney disease 3, 4, 5.
- These studies found that febuxostat may be more effective than allopurinol in reducing serum uric acid levels and slowing renal disease progression 4, 5.
- However, the relationship between vitamin C and uric acid levels is distinct from the comparison of febuxostat and allopurinol, as vitamin C has been shown to have a uricosuric effect 2.