Men with higher vitamin C intake appear less likely to develop gout, a painful type of arthritis, according to a report in the March 9 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
"Gout is the most common type of inflammatory arthritis in men," the authors write as background information in the article. "Epidemiologic studies suggest that the overall disease burden of gout is substantial and growing. The identification of the risk factors for gout that are modifiable with available measures is an important first step in the prevention and management of this common and excruciatingly painful condition."
Hyon K. Choi, M.D., Dr.P.H., then of University of British Columbia, Vancouver, and now of Boston University School of Medicine, and colleagues examined the relationship between vitamin C intake and gout in 46,994 men between 1986 and 2006. Every four years, the men completed a dietary questionnaire, and their vitamin C intake through food and supplements was computed. Every two years, participants reported whether they had been diagnosed with or developed symptoms of gout.
During 20 years of follow-up, 1,317 men developed gout. Compared with men who had a vitamin C intake of less than 250 milligrams per day, the relative risk of gout was 17 percent lower for those with a daily intake of 500 to 999 milligrams, 34 percent lower for those with an intake of 1,000 to 1,499 milligrams per day and 45 percent lower for those with an intake of 1,500 milligrams per day or higher.
For every 500-milligram increase in their vitamin C intake, men's risk for gout appeared to decrease by 17 percent. Compared with men who did not take vitamin C supplements, those who took 1,000 to 1,499 supplemental milligrams per day had a 34 percent lower risk of gout and those who took 1,500 supplemental milligrams per day had a 45 percent lower risk.
Vitamin C appears to reduce levels of uric acid in the blood, the authors note; a buildup of this naturally occurring compound can form crystal deposits in and around joints, leading to the pain, inflammation and swelling associated with gout. Vitamin C may affect reabsorption of uric acid by the kidneys, increase the speed at which the kidneys work or protect against inflammation, all of which may reduce gout risk, the authors note.
"Given the general safety profile associated with vitamin C intake, particularly in the generally consumed ranges as in the present study (e.g., tolerable upper intake level of vitamin C of less than 2,000 milligrams in adults according to the Food and Nutrition Board, Institute of Medicine), vitamin C intake may provide a useful option in the prevention of gout," they conclude.