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

Am J Kidney Dis. 2016 Mar;67(3):400-7. doi: 10.1053/j.ajkd.2015.09.005. Epub 2015 Oct 14.

Abstract

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 (<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.

Limitations: Nutrient intakes derived from food-frequency questionnaires, lack of data on stone composition for all cases.

Conclusions: Total and supplemental vitamin C intake was significantly associated with higher risk for incident kidney stones in men, but not in women.

Keywords: Kidney disease; ascorbic acid; calcium oxalate; diet; food-frequency questionnaire (FFQ); gender difference; incident kidney stone; kidney stone formation; nutrition; risk factor; supplements; urinary oxalate excretion; urolithiasis; vitamin C.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Ascorbic Acid* / metabolism
  • Ascorbic Acid* / pharmacology
  • Body Mass Index
  • Diet / adverse effects*
  • Dietary Supplements / adverse effects*
  • Female
  • Follow-Up Studies
  • Humans
  • Italy / epidemiology
  • Kidney Calculi* / diagnosis
  • Kidney Calculi* / epidemiology
  • Kidney Calculi* / etiology
  • Kidney Calculi* / metabolism
  • Male
  • Middle Aged
  • Prospective Studies
  • Risk Assessment
  • Risk Factors
  • Sex Factors
  • Surveys and Questionnaires
  • United States / epidemiology
  • Vitamins / metabolism
  • Vitamins / pharmacology

Substances

  • Vitamins
  • Ascorbic Acid