What is Calcitonin?


When it comes to hormone health, the thyroid gland has a huge role to play. It produces and controls numerous hormones that affect many aspects of daily life. Calcitonin is one of those critical hormones.

Calcitonin is a hormone that the C-cells in the thyroid gland produce and release. It opposes the action of the parathyroid hormone, helping to regulate the blood’s calcium and phosphate levels.

How does calcitonin work?

Calcitonin works to control calcium and potassium levels. It does this by inhibiting the activity of the osteoclasts, the cells that break down bone. When the osteoclasts break down bone tissue, the calcium enters the bloodstream. By preventing the breakdown of bone, calcitonin lessens the amount of calcium in the blood. The hormone also seems to decrease the amount of calcium the kidneys can re-absorb, lowering levels further.

Secretion of this hormone is controlled directly by the blood’s calcium levels. When the levels start to increase, the body responds with increased calcitonin levels. When calcium levels drop, so do calcitonin levels.

What can go wrong with calcitonin?

Calcitonin is a unique hormone, because its importance is not well known. While doctors know what it does, they do not understand why we have it, and few symptoms occur if levels are high or low. The body appears to function normally, even with high or low levels of this thyroid hormone. In fact, patients who have had their thyroids removed will have virtually no calcitonin levels, but they show no resulting symptoms.

Sometimes high calcitonin levels can point to a rare type of medullary thyroid cancer. This cancer, which starts in the C-cells, can be connected to multiple endocrine neoplasia type 2b and multiple endocrine neoplasia type 2a. However, the calcitonin levels do not cause the cancer.

Questions to ask your doctor

If you have blood work done that indicates high or low calcitonin levels, you may wish to talk to your doctor about the problem to determine if there is an underlying cause or issue with your thyroid. Specifically, if your levels are high, consider asking why or requesting further testing to rule out cancer. Otherwise, high or low calcitonin levels have little affect on your overall health. Still, if you have concerns, talk to an endocrinologist to ensure you are getting support from a hormone specialist. Find an endocrinologist in your area to get started.

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