title: Dietary Zinc and Incident Calcium Kidney Stones in Adolescence.
abstract: We determined the association between dietary zinc intake and incident calcium kidney stones in adolescents. We also examined the relationship between dietary zinc intake and urinary zinc excretion between cases and controls.
  
  
  
  We conducted a nested case-control study within a large pediatric health care system. Three 24-hour dietary recalls and spot urine chemistry analyses were obtained for 30 participants 12 to 18 years old with a first idiopathic calcium based kidney stone and 30 healthy controls matched for age, sex, race and month of enrollment. Conditional logistic regression models were used to estimate the association between daily zinc intake and incident calcium kidney stones, adjusting for dietary phytate, protein, calcium, sodium and oxalate. Multivariable linear regression was used to estimate the association between dietary and urine zinc, adjusting for urine creatinine and dietary phytate and calcium.
  
  
  
  Cases had lower daily zinc intake (8.1 mg) than controls (10 mg, p = 0.029). Daily zinc intake of boys and girls with calcium stones was 2 mg and 1.2 mg less, respectively, than the daily intake recommended by the Institute of Medicine. Odds of incident stones were reduced by 13% for every 1 mg increase in daily zinc intake (OR 0.87, 95% CI 0.75-0.99). There was an estimated 4.5 μg/dl increase in urine zinc for every 1 mg increase in dietary zinc (p = 0.009), with weak evidence of a smaller increase in urine zinc in cases than in controls (interaction p = 0.08).
  
  
  
  Decreased dietary zinc intake was independently associated with incident calcium nephrolithiasis in this population of adolescents.
authors.affiliation: Division of Pediatric Urology, Department of Surgery, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Center for Pediatric Clinical Effectiveness, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Division of Urology, Department of Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania. Electronic address: tasiang@chop.edu.
authors.forename: Gregory E
authors.initials: GE
authors.lastname: Tasian
authors.affiliation: Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; Department of Biostatistics and Epidemiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Michelle E
authors.initials: ME
authors.lastname: Ross
authors.affiliation: Center for Pediatric Clinical Effectiveness, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: Lihai
authors.initials: L
authors.lastname: Song
authors.affiliation: Division of General Pediatrics, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Department of Biomedical and Health Informatics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Grundmeier
authors.affiliation: Department of Biomedical and Health Informatics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: James
authors.initials: J
authors.lastname: Massey
authors.affiliation: Division of Nephrology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Michelle R
authors.initials: MR
authors.lastname: Denburg
authors.affiliation: Division of Nephrology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Copelovitch
authors.affiliation: Division of Pediatric Urology, Department of Surgery, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Center for Pediatric Clinical Effectiveness, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: Steven
authors.initials: S
authors.lastname: Warner
authors.affiliation: Department of Urology, University of California, San Francisco, San Francisco.
authors.forename: Thomas
authors.initials: T
authors.lastname: Chi
authors.affiliation: Center for Nutrition and Metabolism, Children's Hospital Oakland Research Institute, Oakland, California.
authors.forename: David W
authors.initials: DW
authors.lastname: Killilea
authors.affiliation: Department of Urology, University of California, San Francisco, San Francisco.
authors.forename: Marshall L
authors.initials: ML
authors.lastname: Stoller
authors.affiliation: Division of Nephrology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Furth
mesh_terms: D000293:Adolescent; D002118:Calcium / Q000378:metabolism; D016022:Case-Control Studies; D002648:Child; D004032:Diet / Q000009:adverse effects; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D012307:Risk Factors; D016482:Urinalysis; D015032:Zinc / Q000008:administration & dosage* / Q000009:adverse effects / Q000652:urine
chemical_list: D015032:Zinc; D002118:Calcium
keywords: kidney calculi; nutritional status; pediatrics; zinc