Calcitonin Hormone Test - Calcitonin Test

A calcitonin test is a quantitative measurement of the serum level of the hormone calcitonin. This hormone is primarily secreted by the parafollicular cells (C cells) of the thyroid gland. Its main physiological function is to lower blood calcium levels by inhibiting bone resorption. Significantly elevated calcitonin levels are a hallmark of medullary thyroid carcinoma (MTC).