More than 99% of the total body calcium is stored ashydroxyapatite and less than 1% of calcium circulates in the blood. In plasma, circulating calcium is approximately 45% albumin-bound; 40% exists in an ionized form; and about 15% is found as anionic salts (e.g., calcium citrate, calcium phosphate, and calcium carbonate). Common causes for hypocalcemia include hypoparathyroidism, vitamin D deficiency or resistance, renal or liver failure and some drugs. The clinical presentations of hypocalcemia range from asymptomatic disease to lethal arrhythmia. Acute hypocalcemia can result in severe symptoms that require rapid correction and treat underlying causeis the cornerstone of managing hypocalcemia.