Calcium, 24 Hour Urine

Message

Test performed at York Hospital Laboratory.

Test Code

UCAL24

CPT Codes
82340

Preferred Specimen

20 mL aliquot of a well mixed 24-hour urine, submitted in a plastic leakproof container

Instructions

York Back Lab: After urine collection, add 6N HCl to a well mixed aliquot of 24 hour urine to maintain a pH of 1.5 - 5.0.

Transport Temperature

Refrigerated

Specimen Stability

Room temperature: 5 days Refrigerated: 5 weeks Frozen: 6 months

Methodology
Colorimetric

Setup Schedule

Daily

Report Available

Next day

Reference Range

Dietary Calcium Intake

Ca-free	5-40 mg/day
Low to average	50-150 mg/day
Average	100-300 mg/day

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.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.