Thyrocalcitonin, also known as calcitonin, refers to a protein hormone secreted and produced in humans and other mammals mainly by the C cells or parafollicular cells in the thyroid gland.
Calcitonin lowers the concentration of calcium in the blood when it elevates above the normal value.
It also reduces the concentration of phosphorus in the blood when the levels increase above the normal.
It also prevents the activity of the osteoclasts in bone tissue, thus inhibiting the breakdown of bone, and preventing the reabsorption of calcium by the kidney cells, leading to an enhanced excretion of calcium in the urine.