Question

Name the hormone that regulates the rise in calcium ion level in the blood.

Answer 1

Parathyroid hormone (PTH) increases the Ca${}^{2+}$levels in the blood. PTH acts on bones and stimulates the process of bone resorption (dissolution/demineralisation). PTH also stimulates reabsorption of Ca${}^{2+}$ by the renal tubules and increases Ca2+ absorption from the digested food. Hence, PTH is a hypercalcemic hormone, i.e., it increases the blood Ca${}^{2+}$ levels.