In most cases, this condition is caused by an underlying condition called primary hyperparathyroidism or overactive parathyroid glands. These glands are found either on or around the thyroid gland and produce parathyroid hormone, which, along with calcitonin (one of the hormones produced by the thyroid gland), play key roles in regulating the amount of calcium in the blood and bones. Immobility can lead to calcemia because over time, bones that don’t bear weight release calcium into the blood.
In other cases, certain cancers, medical conditions, medications and extensive consumption of calcium and vitamin D supplements can cause calcemia. Certain drugs like lithium (which is used to treat bipolar disorder) also can increase levels of parathyroid hormone, which can lead to more calcium being released into the blood. Rarely, a genetic disorder known as familial hypocalciuric hypercalcemia can cause an increase in the calcium in the blood because of faulty calcium receptors in the body. Dehydration may be a temporary cause for mild calcemia because when there is less fluid in the body, calcium concentrations rise.
Calcium is a key mineral for many body functions, including bone formation and health, hormone release, muscle contraction, and nerve and brain function. Along with parathyroid hormone, the body’s vitamin D manages this nutrient, which is obtained when the skin is exposed to sunlight and from dietary sources such as eggs, dairy, fish and fortified cereals.
When the body doesn’t have enough calcium, the parathyroid glands release the hormone that triggers bones to release calcium into the blood, tells the digestive tract to absorb more calcium, and the kidneys to excrete less calcium and activate more vitamin D, which boosts calcium absorption. However, more isn’t always more. As with many nutrients, the key to maintaining good health is to maintain the delicate balance your body needs.