Preferred Specimen(s): 10 mL random Urine. Collect urine with 25 mL 6N HCL
Transport Container: Sterile urine container or Plastic screw urine vial Transport
Temperature
- Refrigerated preferred;
- Room temperature acceptable;
- Frozen acceptable
Reject Criteria: None
Methodology: Spectrophotometry
Clinical Significance: Urinary calcium reflects dietary intake, rate of calcium absorption by the intestine and bone resorption. Urinary calcium is used primarily to evaluate parathyroid function and the effects of Vitamin D. A significant number of patients with primary hyperparathyroidism will have elevated urinary calcium. However, there are other clinical entities that may be associated with increased urine calcium: Sarcoidosis, Paget’s disease of bone, Vitamin D intoxication, hyperthyroidism and glucocorticoid excess. Decreased urine calcium is seen with thiazide diuretics, vitamin D deficiency and familial hypocalciuric hypercalcemia.