Incidence of normocalcemic hyperparathyroidism in idiopathic hypercalciuria: evaluation by dietary calcium deprivation test

Eur Urol. 1981;7(6):331-4. doi: 10.1159/000473258.


Calcium metabolism was studied in 37 patients with "idiopathic hypercalciuria" on a home diet and after 10 days of low calcium dietary intake (less than 400 mg/24h). After low calcium intake, urinary calcium excretion returned to within normal limits in 70% of the cases. In the group of patients which failed to respond to calcium restriction, TmPO4/GFR values were reduced and, furthermore, in 20% of them plasma iPTH and urinary cAMP levels were increased. These data seem to indicate that: the incidence of absorptive hypercalciuria is higher than hypercalciuria of renal origin; normocalcemic hyperparathyroidism due to primary calcium leak is present only in a limited number of cases, consequently, hypercalciuria secondary to renal phosphate leak is a rather frequent occurrence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium / blood
  • Calcium / metabolism
  • Calcium / urine*
  • Calcium, Dietary*
  • Cyclic AMP / urine
  • Diagnosis, Differential
  • Female
  • Glomerular Filtration Rate
  • Humans
  • Hyperparathyroidism / complications*
  • Kidney / metabolism
  • Male
  • Parathyroid Hormone / blood
  • Phosphates / blood
  • Sex Factors
  • Urinary Calculi / etiology*


  • Calcium, Dietary
  • Parathyroid Hormone
  • Phosphates
  • Cyclic AMP
  • Calcium