Oxalate and calcium excretion in cystic fibrosis

Arch Dis Child. 2000 Sep;83(3):244-7. doi: 10.1136/adc.83.3.244.


Background: A patient with cystic fibrosis (CF) and repeated calcium oxalate renal stones prompted us to investigate other children for risk factors for this recognised complication of CF.

Methods: Twenty four hour urinary excretion of calcium, oxalate, and glycolate was measured in children with CF and no symptoms of renal tract stones. Normal diet and treatments were continued.

Results: In 26 children (aged 5-15.9 years) oxalate excretion was correlated with age; 14 of 26 children had oxalate excretion above an age appropriate normal range. There was a positive correlation between oxalate excretion and glycolate excretion. Mean calcium excretion was 0.06 mmol/kg/24 h with 21 of 24 children having calcium excretion below the normal range.

Conclusions: Hyperoxaluria may reflect malabsorption although correlation between excretion of oxalate and glycolate suggests a portion of the excess oxalate is derived from metabolic processes. The hypocalciuria observed here may protect children with CF from renal stones.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Calcium Oxalate / urine*
  • Child
  • Child, Preschool
  • Cross-Sectional Studies
  • Cystic Fibrosis / complications
  • Cystic Fibrosis / urine*
  • England / epidemiology
  • Humans
  • Hyperoxaluria / epidemiology
  • Hyperoxaluria / metabolism
  • Hyperoxaluria / urine*
  • Prevalence
  • Regression Analysis
  • Urinary Calculi / urine


  • Calcium Oxalate