Use of random urine samples to estimate total urinary calcium and phosphate excretion

Arch Intern Med. 1991 Aug;151(8):1587-8. doi: 10.1001/archinte.1991.00400080083015.


Calcium-to-creatinine and phosphate-to-creatinine ratios in random single-voided urine specimens were compared with 24-hour calcium and phosphate excretions, respectively, in 67 subjects who were selected prospectively to represent a wide range of renal and parathyroid function as well as urinary calcium and phosphate loss. Simple linear regression analysis revealed significant correlation between the spot urine calcium-to-creatinine ratio and 24-hour total calcium excretion and between the spot urine phosphate-to-creatinine ratio and 24-hour phosphate excretion. Calculating these simple ratios permits easy, rapid, correct, and inexpensive estimation of the daily urinary calcium and phosphate excretion.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Calcium / urine*
  • Creatinine / urine
  • Female
  • Humans
  • Kidney Failure, Chronic / urine
  • Male
  • Middle Aged
  • Monitoring, Physiologic
  • Phosphates / urine*
  • Prospective Studies
  • Random Allocation
  • Reference Values
  • Regression Analysis


  • Phosphates
  • Creatinine
  • Calcium