Most people have heard that calcium helps keep your bones and teeth strong. What you might not realize is that the mineral is essential to several other vital bodily functions, including nerve messaging, normal heart function and muscle contractions. The calcium in your body is measured through a blood test; normal values range between 8.5 and 10.2 mg/dL, according to Medline Plus. Underlying health conditions may be the reason why you have too much calcium in your blood, a condition called hypercalcemia. Hypercalcemia can lead to osteoporosis, kidney stones and heart arrhythmias.
Hyperparathyroidism
You might measure on the side of too much calcium on your blood test if your parathyroid glands are working overtime, a condition called hyperparathyroidism. Your parathyroids are tiny pea-sized glands in your neck that secrete hormones to keep your phosphorus and calcium levels balanced. If you have a tumor -- benign or malignant -- on one of these four glands, you may make more of the parathyroid hormone -- PTC -- than you should. Because the hormones keep your calcium balances in check, an overage of PTC can raise your blood calcium levels.
Cancer
Bone cancer or a cancerous tumor on one of your parathyroid glands can lead to hypercalcemia in some people. Cancerous cells that live in your bones produce substances that affect other cells in your bones, called osteoclasts. Osteoclasts cause your bones to dissolve, which may cause you to store too much calcium in your blood. The effects of any type of cancer, mainly the need for significant periods of rest, can also be a factor in hypercalcemia. Bearing weight through walking and other forms of exercise helps protect your bones from osteoporosis and keeps the calcium levels stable. If you don't bear weight often, the calcium found in your bones can leach out into your blood stream, causing your serum calcium levels to rise above normal.
Lung Diseases
Two forms of lung disease, both of which are rarely seen in the United States, can cause you to have too much calcium in your blood. Tuberculosis, an infectious disease, and sarcidossis, a non-infectious inflammatory lung condition, can cause your vitamin D levels to rise. This spike in vitamin D tells your body to absorb more calcium during the digestive process. The more calcium you absorb, the higher your blood levels become.
Medications and Supplements
Hypercalcemia may have nothing to do with underlying illness, but may be provoked by medications, vitamin supplements and the amount of dietary calcium you take. The two most common examples for drug-induced hypercalcemia are lithium and the thiazide class of diuretics. Lithium, often prescribe to treat certain forms of mental illness, can increase your production of parathyroid hormones. Certain diuretics can cause you to hold on to more calcium than normal because you excrete less than the usual amounts in your urine. If you take large doses of vitamin D or calcium supplements, you might also be at risk of measuring high on a calcium blood test.
