Total, Dietary, and Supplemental Vitamin C Intake and Risk of Incident Kidney Stones

Background Previous studies of vitamin C and kidney stones were conducted mostly in men and either reported disparate results for supplemental and dietary vitamin C or did not examine dietary vitamin C. Study Design Prospective cohort analysis. Setting & Participants 156,735 women in the Nurses’ Health Study (NHS) I and II and 40,536 men in the Health Professionals Follow-up Study (HPFS). Predictor Total, dietary, and supplemental vitamin C intake, adjusted for age, body mass index, thiazide use, and dietary factors. Outcomes Incident kidney stones. Results During a median follow-up of 11.3 to 11.7 years, 6,245 incident kidney stones were identified. After multivariable adjustment, total vitamin C intake (