Ascorbic Acid Supplements Linked to Kidney Stones

By Kelly Young

Use of vitamin C (ascorbic acid) supplements is associated with development of kidney stones in men, according to a study in JAMA Internal Medicine.

Nearly 50,000 men in Sweden completed questionnaires about their use of ascorbic acid. Over 11 years' follow-up, 0.9% developed kidney stones. Men who reported using ascorbic acid had nearly double the risk for incident kidney stones (adjusted relative risk, 1.92). Doses and brands were not available, but ascorbic acid supplements in Sweden typically contain 1000 mg per tablet.

The authors conclude: "Currently there are no well-documented benefits of high-dose ascorbic acid supplement use, and, therefore, it seems prudent to advise that high-dose preparations be avoided, particularly by those with a history of kidney stones."