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

• Published in: American journal of kidney diseases Vol. 67; no. 3; pp. 400 - 407
• Main Authors: Ferraro, Pietro Manuel, Curhan, Gary C., Gambaro, Giovanni, Taylor, Eric N.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2016
• Subjects: Adult; Aged; ascorbic acid; Ascorbic Acid - metabolism; Ascorbic Acid - pharmacology; Body Mass Index; calcium oxalate; diet; Diet - adverse effects; Dietary Supplements - adverse effects; Female; Follow-Up Studies; food-frequency questionnaire (FFQ); gender difference; Humans; incident kidney stone; Italy - epidemiology; Kidney Calculi - diagnosis; Kidney Calculi - epidemiology; Kidney Calculi - etiology; Kidney Calculi - metabolism; Kidney disease; kidney stone formation; Male; Middle Aged; Nephrology; nutrition; Prospective Studies; Risk Assessment; risk factor; Risk Factors; Sex Factors; supplements; Surveys and Questionnaires; United States - epidemiology; urinary oxalate excretion; urolithiasis; vitamin C; Vitamins - metabolism; Vitamins - pharmacology; United States; Italy; Kidney disease; ascorbic acid; vitamin C; kidney stone formation; gender difference; incident kidney stone; calcium oxalate; risk factor; supplements; urinary oxalate excretion; nutrition; food-frequency questionnaire (FFQ); urolithiasis; diet
• ISSN: 0272-6386; 1523-6838; 1523-6838
• DOI: 10.1053/j.ajkd.2015.09.005

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. Prospective cohort analysis. 156,735 women in the Nurses’ Health Study (NHS) I and II and 40,536 men in the Health Professionals Follow-up Study (HPFS). Total, dietary, and supplemental vitamin C intake, adjusted for age, body mass index, thiazide use, and dietary factors. Incident kidney stones. 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 (<90 [reference], 90-249, 250-499, 500-999, and ≥1,000mg/d) was not significantly associated with risk for kidney stones among women, but was among men (HRs of 1.00 [reference], 1.19 [95% CI, 0.99-1.46], 1.15 [95% CI, 0.93-1.42], 1.29 [95% CI, 1.04-1.60], and 1.43 [95% CI, 1.15-1.79], respectively; P for trend = 0.005). Median total vitamin C intake for the 500- to 999-mg/d category was ∼700mg/d. Supplemental vitamin C intake (no use [reference], <500, 500-999, and ≥1,000mg/d) was not significantly associated with risk for kidney stones among women, but was among men (HR, 1.19 [95% CI, 1.01-1.40] for ≥1,000mg/d; P for trend = 0.001). Dietary vitamin C intake was not associated with stones among men or women, although few participants had dietary intakes > 700mg/d. Nutrient intakes derived from food-frequency questionnaires, lack of data on stone composition for all cases. Total and supplemental vitamin C intake was significantly associated with higher risk for incident kidney stones in men, but not in women.