Thyroidectomy is the removal of the thyroid gland. This invasive surgical procedure must be performed carefully to prevent the accidental removal of parathyroid glands, which are located on the back surface of the thyroid gland. Accidental removal of the parathyroid glands can result in low blood calcium. The monitoring of blood calcium levels after thyroidectomy is important in preventing complications associated with calcium imbalance.
Reason For Performing Thyroidectomy
Thyroid removal surgery is usually performed when a person has thyroid cancer; the purpose is to prevent compression of structures in the neck and the spread of the cancer. Thyroidectomy is also a treatment for other conditions such as goiter, a cosmetically unpleasant swelling in the thyroid. During pregnancy, thyroidectomy is the best treatment for an overactive thyroid as other treatment options can potentially harm the baby, according to "Davidson's Principles & Practice of Medicine."
Functions of Calcium
Calcium is necessary for strong bones. While most calcium in the body is found in the bones, a small percentage of total body calcium is also found in the blood. Adequate blood calcium levels must be maintained to prevent abnormal heart function because the cardiac pacemakers -- a group of cells that determine the heart rate -- require adequate calcium to function properly. The passage of digested food through the intestines also requires adequate levels of blood calcium; abnormal calcium concentration may result in either diarrhea or constipation.
Regulation of Calcium
Blood calcium is maintained by dietary intake of calcium or from calcium in bones.The thyroid and parathyroid glands are the main regulators of blood calcium. When blood calcium is low, the parathyroid gland releases the parathyroid hormone, which cause the breakdown of bone to release calcium to the blood. When blood calcium is high, the thyroid gland releases calcitonin, a hormone which removes excess calcium from the blood.
Calcium Supplementation
The accidental removal of the parathyroid gland means bone calcium cannot be used to replenish blood calcium. Decreased blood calcium must be corrected by increased dietary calcium intake, calcium and vitamin supplementation and parathyroid hormone supplementation. Vitamin D facilitates calcium absorption and would therefore be beneficial in the restoration of adequate blood calcium levels. According to the "Osteoporosis International," calcium can be supplemented at 3,000 mg per day and vitamin D at 0.6 micrograms per day; with the addition of parathyroid hormone to regimen, smaller doses of calcium and vitamin D were needed to maintain adequate bone density.
References
- "Osteoporosis International"; Therapy of hypoparathyroidism with intact parathyroid hormone; M. R. Rubin, et al.; January 2010
- "Harrison's Principles of Internal Medicine"; Dennis L. Kasper M.D., et al.; 2005
- "Davidson's Principles & Practice of Medicine; Nicholas A. Boon; 2006
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