Calcitonin, a 32-amino-acid polypeptide, is secreted primarily by the thyroidal parafollicular C-cells. Its main biological effect is to inhibit osteoclastic bone resorption as well as playing a role in calcium and phosphorus metabolism in the bone and kidney. Calcitonin supresses resorption of bone by inhibiting the activity of osteoclasts releasing calcium and phosphorus into blood. In the kidney, calcium and phosphorus are prevented from being lost in urine by reabsorption in the kidney tubules. Calcitonin inhibits tubular reabsorption of these two ions, leading to increased rates of their loss in urine.

Related Terms/Symbols:- CALCA gene- CALCA1 gene- P01258- CALC_HUMAN