Vitamin C has been touted as a preventive for problems ranging from cancers to the
common cold. But can a daily vitamin C supplement protect you from gout? Possibly, researchers say, but results of studies on vitamin C and gout are mixed.
In a 2009 study published in the Archives of Internal Medicine, Hyon K. Choi, MD, of the Boston University School of Medicine, showed that the more vitamin C men took, the less likely they were to get gout.
During the 20 years that researchers studied nearly 47,000 men, 1,317 of them developed gout. But the risk was not shared equally. For every 500-milligram increase in vitamin C intake, the risk for gout fell by 17 percent. The risk dropped by 45 percent when study participants took more than 1,500 mg of vitamin C a day.
Vitamin C is believed to protect against gout by lowering serum urate, thought to be due to greater removal of urate through the kidneys, says Tuhina Neogi, MD, PhD, associate professor of medicine at Boston University School of Medicine. While vitamin C intake was associated with a lower risk of developing gout, the effect of vitamin C among people with gout is less clear, she says.
In a 2013 study published Arthritis & Rheumatism, a modest vitamin C dose failed to reduce uric acid levels to a clinically significant degree in patients with established gout.
Of the 40 participants with gout, 20 patients already taking allopurinol, a drug that helps the kidney excrete uric acid, were given an additional 500-mg dose of vitamin C daily or had the dose of allopurinol increased. The other 20 participants, who were not already taking allopurinol, were either started on allopurinol or vitamin C (500 mg/day). Researchers analyzed blood levels of vitamin C (ascorbate), creatinine and uric acid at baseline and week eight.
The study found that reduction of uric acid was significantly less in gout patients taking vitamin C compared to those who started or increased their dose of allopurinol.
The effect of vitamin C among people with gout needs further study, says Dr. Neogi, who was not involved with the study. “In addition to understanding whether there are true benefits for people with gout, the amount of vitamin C that would be ideally effective without causing some of the harmful side effects of excessive vitamin C (such as kidney stones) will also need to be determined.”