Calcium is essential to the proper functioning of the body.  Not only is calcium needed for strong bones and teeth, but it is also is needed for proper heart functions, muscles, communication between cells and to enable blood to clot.

Because of calcium’s importance to a healthy body, a blood calcium test is normally ordered as part of a regular physical.  This test cannot tell you if you have a deficiency of calcium in your bones, but only if there are lower amounts of calcium in the blood.  A frequently ordered test for bone density is called a Dexa scan.

If the blood calcium is low, your doctor may order other tests to investigate if your bones are getting sufficient calcium.  

Because about 50% of the calcium in the blood is attached to proteins, a test of the free calcium is sometimes ordered, called a free calcium test, to ensure that you have the proper balance between free calcium and protein bound calcium.  Improper balance of free calcium in the blood can affect the heart and the muscles. 

NORMAL RESULTS

Normal values range from 8.5 to 10.2 mg/dL (milligrams per a tenth of a liter).

LOWER THAN NORMAL RESULTS

If the results are lower than normal, then it may indicate:
Hypoparathyroidism (low production of the parathyroid hormone which regulates the balance of calcium and phosphorus)
• Kidney problems
Liver problems
• Low magnesium
Osteomalacia (weakening of the bones often caused by vitamin D deficiency)
Pancreatitis (inflammation of the pancreas)
• Low vitamin D 

HIGHER THAN NORMAL RESULTS

If results are higher than normal, then it may indicate:
• Taking too much calcium
• Taking too much vitamin D
HIV/AIDS
Hyperparathyroidism (high production of the parathyroid hormone which regulates the balance of calcium and phosphorus)
• Bone tumor
Myeloma (cancer involving white blood cells)
Thyroid problems
• Paget’s disease (bones enlarge and become weaker)
• Sarcoidosis (inflammation of the lungs, skin or lymph nodes)