Dietary Risk Factors for Pediatric Kidney Stones: A Case-Control Study

J Urol. 2022 Aug;208(2):434-440. doi: 10.1097/JU.0000000000002687. Epub 2022 Apr 4.


Purpose: Data are scarce regarding dietary risk factors for pediatric nephrolithiasis. Our objective was to perform a case-control study (nonmatched) of the association of dietary nutrients with pediatric urolithiasis.

Materials and methods: We obtained dietary information from pediatric urolithiasis patients (from stone clinic in 2013-2016) and healthy controls (well-child visit at primary care in 2011-2012). Survey results were converted to standard nutrient intakes. Children younger than 5 years of age and those with extreme calorie intake values (<500 or >5,000 kcal/day) were excluded. The association of individual nutrients with urolithiasis was assessed by bivariate analysis results and machine-learning methods. A multivariable logistic regression model was fitted using urolithiasis as the outcome.

Results: We included 285 patients (57 stones/228 controls). Mean±SD age was 8.9±3.6 years (range 5-20). Of the patients 47% were male. After adjusting for age, sex, body mass index (obese/overweight/normal), calorie intake and oxalate, urolithiasis was associated with higher dietary sodium (OR=2.43 [95% CI=1.40-4.84] per quintile increase, p=0.004), calcium (OR=1.73 [95% CI=1.07-3.00] per quintile increase, p=0.034) and beta carotene (OR=2.01 [95% CI=1.06-4.18] per quintile increase, p=0.042), and lower potassium (OR=0.31 [95% CI=0.13-0.63] per quintile increase, p=0.003). Sensitivity analysis was performed by removing oxalate from the model and limiting the sample to patients aged 5-13 years, with similar results.

Conclusions: In our cohort, higher dietary intake of calcium, sodium and beta carotene, and lower potassium intake were associated with pediatric urolithiasis. This is the first study using a detailed dietary survey to identify dietary risk factors for pediatric urolithiasis. Further research is warranted to delineate the mechanisms and to generate a lower risk diet profile for pediatric urolithiasis.

Keywords: diet records; kidney calculi; machine learning; pediatrics; urolithiasis.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Calcium
  • Calcium, Dietary / adverse effects
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Diet / adverse effects
  • Female
  • Humans
  • Kidney Calculi* / epidemiology
  • Kidney Calculi* / etiology
  • Male
  • Oxalates
  • Potassium
  • Risk Factors
  • Urolithiasis* / complications
  • beta Carotene


  • Calcium, Dietary
  • Oxalates
  • beta Carotene
  • Potassium
  • Calcium