Video - Calcitonin

Calcitonin is a polypeptide hormone that regulates calcium levels in the blood. It is secreted by the parafollicular cells (C cells) of the thyroid gland in response to elevated serum calcium levels. Calcitonin lowers serum calcium by inhibiting calcium release from bone marrow and slowing down the absorption of dietary calcium.

Calcitonin plays a crucial role in maintaining calcium homeostasis; thus, its blood levels are tightly regulated. Elevated calcitonin levels are seen in conditions such as hyperthyroidism and thyroid malignancy.