We all need calcium. It’s categorized as a mineral and is found almost entirely in the bones. In addition to strengthening the bones, it helps muscles contract, helps nerves/brain function and assists in the regulation of heart rhythms and blood pressure. But like anything else, too much of a good thing can be dangerous.
High blood calcium (hypercalcemia) is like it sounds -– too much calcium in the blood. Some persons have slightly high levels of calcium with no symptoms. This is no cause for alarm. Your doctor will just monitor this area for any changes at your annual check-ups. However, there are times when the calcium levels are so high that it causes damage to the body.
Symptom and Causes
Symptoms for severe hypercalcemia are as follows:
Nausea and vomiting
Loss of appetite
Muscle and joint pain
Lethargy and fatigue
Normally, when calcium decreases, the body knows to produce more parathyroid hormone and when calcium increases, it knows to produce less. The parathyroid hormone is responsible for stimulating the bones to produce more calcium, the digestive system to absorb it, and the kidneys to produce less of it while producing more vitamin D. Vitamin D helps in calcium absorption as well.
When the calcium levels reach a very high point, the thyroid gland releases the hormone, calcitonin. This hormone slows the rate of calcium being released from your bones. However, with hypercalcemia, this process is disrupted. This can be caused by a number of factors, such as:
Overactive parathyroid gland – this is the main cause of hypercalcemia.
Cancer - with some cancers (breast, lung and multiple myeloma) the malignant tumor actually produces a protein that mimics the parathyroid hormone and tricks the body to produce more calcium than needed.
Other diseases – such as, tuberculosis and sarcoidosis, cause inflammation where tissue is injured and as a result, raises vitamin D levels. Elevated vitamin D (calcitriol) makes your digestive system absorb more calcium, causing the body to produce more at a faster rate.