Summary
The major clinical value of urine calcium is to guide the clinician in determining the cause as well as the best treatment options for patients who present with disease related to inappropriate calcium metabolism. The concentration of calcium in urine reflects serum calcium. Many types of urine crystals contain calcium, and random and 24-hour collections are used to assess urine calcium concentration. Primarily, testing is performed to supplement serum testing. No disease is definitively ruled in or out with urine calcium measurement, but the test can be a useful tool when putting together a complete picture of electrolyte homeostasis in the search for a pathology. Urine calcium is often ordered to help assess parathyroid disease and FHH. Although not predictive of stone formation, urine calcium is often elevated in patients with lithiasis.
Abbreviations
FHH, familial hypocalciuric hypercalcemia; RDA, recommended dietary allowance; PTH, parathyroid hormone; CaCO3, calcium carbonate; CaHPO4 or Ca[H2PO4]2, calcium phosphate; CASR, calcium-sensing receptor; CE, calcium excretion; CR, 24-hour urine calcium/creatinine excretion ratio; CCCR, calcium/creatinine clearance ratio; FEca, fractional excretion of calcium; PH, primary hyperparathyroidism
Lab Med. 2010;41(11):683-686. © 2010 American Society for Clinical Pathology
Cite this: Urine Calcium: Laboratory Measurement and Clinical Utility - Medscape - Nov 01, 2010.
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