title: Total, Dietary, and Supplemental Vitamin C Intake and Risk of Incident Kidney Stones.
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.
  
  
  METHODS
  Prospective cohort analysis.
  
  
  METHODS
  156,735 women in the Nurses' Health Study (NHS) I and II and 40,536 men in the Health Professionals Follow-up Study (HPFS).
  
  
  METHODS
  Total, dietary, and supplemental vitamin C intake, adjusted for age, body mass index, thiazide use, and dietary factors.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of Nephrology, Department of Medical Sciences, Columbus-Gemelli University Hospital, Catholic University of the Sacred Heart, Rome, Italy; Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA. Electronic address: manuel.ferraro@channing.harvard.edu.
authors.forename: Pietro Manuel
authors.initials: PM
authors.lastname: Ferraro
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.
authors.forename: Gary C
authors.initials: GC
authors.lastname: Curhan
authors.affiliation: Division of Nephrology, Department of Medical Sciences, Columbus-Gemelli University Hospital, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Gambaro
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; Division of Nephrology and Transplantation, Maine Medical Center, Portland, ME.
authors.forename: Eric N
authors.initials: EN
authors.lastname: Taylor
mesh_terms: D000328:Adult; D000368:Aged; D001205:Ascorbic Acid / Q000378:metabolism / Q000494:pharmacology; D015992:Body Mass Index; D004032:Diet / Q000009:adverse effects*; D019587:Dietary Supplements / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007558:Italy / Q000453:epidemiology; D007669:Kidney Calculi / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D014815:Vitamins / Q000378:metabolism / Q000494:pharmacology
chemical_list: D014815:Vitamins; D001205:Ascorbic Acid
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