Tinawi, Mohammad2022-05-272022-05-272021-01-01Tinawi M. Disorders of Calcium Metabolism: Hypocalcemia and Hypercalcemia. Cureus. 2021;13(1):e12420. Published 2021 Jan 1. doi:10.7759/cureus.12420https://hdl.handle.net/1805/29188Calcium (Ca+2) is a divalent cation that plays a critical role in numerous body functions such as skeletal mineralization, signal transduction, nerve conduction, muscle contraction, and blood coagulation. Ca+2 metabolism is linked to magnesium (Mg+2) and phosphate metabolism. Ca+2 homeostasis is dependent on intestinal absorption, bone turnover, and renal reabsorption. The hormonal regulators of these processes are the parathyroid hormone (PTH), calcitriol {1,25-dihydroxyvitamin D [1,25(OH)2D]}, and serum ionized Ca+2. Cloning of the Ca+2-sensing receptor (CaSR) has greatly advanced the understanding of Ca+2 metabolism. Disorders of Ca+2 metabolism are easily recognized because Ca+2 is included in routine chemistry panels. Measurement of ionized Ca+2 is the preferred way to ascertain the diagnosis of hypocalcemia and hypercalcemia.en-USAttribution 4.0 InternationalCalcium metabolismCalcium sensing receptorElectrolyte disordersHypercalcemiaHypocalcemiaArticle