Calcitonin is a hormone produced in thymus glands, the parathyroid and the parafollicular cells, also called c-cells, of the thyroid. The apparent function of this hormone is to lower the amount of calcium in the blood and to increase calcium and phosphate deposits in the bones, a positive force in maintaining bone density. Factors which can influence calcitonin levels include nutrition, age, gender and the presence of certain diseases.
If calcitonin levels are elevated it may be an indication of medullary thyroid cancer, the third most common form of thyroid cancer, which begins in the c-cells where calcitonin is produced. A thyroidectomy, or removal of the thyroid gland, is usually performed and may be followed by radiation treatments. After the tumor has been removed a patient will continue to have periodic tests to check levels of calcitonin in the blood; if levels dramatically increase it can indicate that the cancer has returned.
Elevated calcitonin levels also occur in the presence of bone cancer. The disease interferes with the ability of the bones to maintain calcium which further hastens the ability of the cancer to metastasize bone matter. Physicians often administer salmon-derived calcitonin through injections or nasal sprays to bone cancer patients to increase their calcitonin levels and slow down bone loss.
Paget’s disease causes a breakdown of existing bone that is replaced by new, weaker bones and sometimes results in deformities. Elevated phosphate levels in the blood can be an indication of Paget’s and treatment may include calcitonin injections to increase calcitonin levels in the blood. The increased calcitonin helps the bones to retain more calcium and mass.
Long-term calcium and Vitamin D deficiencies can affect calcitonin levels as well because the bones and teeth are not receiving sufficient calcium to maintain optimum mass and strength. If nutritional deficiencies are responsible for the calcitonin changes doctors generally recommend calcium supplements and increased vitamin D. Vitamin D deficiencies can be corrected with supplements or by spending daily time outdoors absorbing the natural vitamin D in sunlight through the skin.
Age and gender are also factors in abnormal calcitonin levels and some studies indicate that these changes in postmenopausal women may increase the likelihood of osteoporosis, a loss of bone density that makes bones more susceptible to fractures. While more studies need to be conducted, it does appear that postmenopausal women with osteoporosis who are treated with calcitonin have improved bone density. The FDA has authorized a calcitonin nasal spray to treat osteoporosis in women as well as patients with Paget’s disease and those who have a condition called hypercalcemia, or high blood calcium.