Clinical Significance

Calcitonin (CT) is a hormone produced primarily by the parafollicular cells (also known as C-cells) of the thyroid gland in humans.  It plays a key role in calcium and phosphate metabolism, helping to regulate blood calcium levels.

Calcitonin is sometimes used therapeutically to treat hypercalcemia (abnormally high levels of calcium in the blood), particularly when it results from conditions such as hyperparathyroidism, certain cancers, or prolonged immobilization. While not a first-line treatment, calcitonin may be used in some cases of osteoporosis to reduce bone resorption and alleviate pain associated with vertebral fractures.