Urinary calcium (UCa)

Urinary calcium represents the quantity of calcium ions eliminated through the renal system, serving as a vital indicator of systemic mineral homeostasis and renal function [StatPearls, NBK448183]. It is not a molecular target in the traditional sense, such as a protein or receptor, but rather a clinical analyte used to assess the risk of nephrolithiasis and metabolic bone disorders [Mayo Clinic, 2023]. The excretion of calcium is regulated by a complex interplay of filtration at the glomerulus and reabsorption in various segments of the nephron, influenced by parathyroid hormone, vitamin D, and the calcium-sensing receptor [PubMed, 12623921]. Pharmacological agents such as thiazide diuretics are employed to decrease urinary calcium levels to prevent kidney stones by promoting reabsorption in the distal tubule [PubChem, CID 3639]. Conversely, loop diuretics like furosemide increase calcium excretion and are utilized in treating symptomatic hypercalcemia [StatPearls, NBK532965]. Monitoring urinary calcium is essential for managing conditions like primary hyperparathyroidism, sarcoidosis, and idiopathic hypercalciuria [NIH, 2022].

Other names

Urine calciumUrinary Ca2+24-hour urine calciumCalcium excretion

Drugs do not directly bind to urinary calcium; instead, they modulate its levels by acting on renal transporters (e.g., Sodium-chloride symporter, Sodium-potassium-chloride cotransporter) or systemic regulators like the Calcium-sensing receptor (CaSR) and Parathyroid hormone (PTH) pathways to alter renal reabsorption and intestinal absorption.