Calcium plays a very important role in the formation of bones.

Thyroid gland and the parathyroid gland that is an antagonist with each other are responsible for maintaining calcium homeostasis. Calcitonin is responsible for the high

calcium level in the blood.

It also decreases plasma calcium concentration by decreasing mobilization of calcium from bones. Parathyroid hormone increases the calcium level in blood which is secreted by the parathyroid gland. It increases the reabsorption of calcium by renal tubules of the kidney.