Total and supplemental vitamin C intake is associated with a significantly elevated risk of kidney stones in men, according to a new study published online ahead of print in the American Journal of Kidney Diseases.
In a prospective cohort analysis, Pietro Manuel Ferraro, MD, of Columbus-Gemelli University Hospital, Catholic University of the Sacred Heart in Rome, Italy, and colleagues found that total vitamin C intake of 90–249, 250–499, 500–999, and 1,000 mg/day or higher was associated with a 19%, 15%, 29%, and 43% increased risk of kidney stones among men compared with an intake below 90 mg/day (reference). The researchers found no association between total vitamin C intake among women.
Additionally, Dr. Ferraro’s group found that high supplemental vitamin C intake was associated with an increased risk of kidney stones in men, but not women. Supplemental vitamin C intake of 1,000 mg/day or more by men was associated with a significant 19% increased risk of kidney stones compared with no intake. Dietary vitamin C intake was not associated with kidney stone risk in either men or women.
The study included 156,735 women in the Nurses’ Health Study I and II and 40,536 men in the Health Professionals Follow-up Study.
The researchers acknowledged that their study was limited by the use of food-frequency questionnaires to ascertain nutrient intake and a lack of data on stone composition.