A serum calcium blood test measures the total calcium in your blood. There are several different forms of calcium in your blood. These include ionized calcium, calcium bound to other minerals called anions, and calcium bound to proteins like albumin. Ionized calcium, also known as free calcium, is the most active form.
Doctor may want to check your blood calcium levels if you have signs of kidney disease, certain kinds of cancers, or problems with your parathyroid gland.
In adults, a level of 4.64 to 5.28 milligrams per deciliter (mg/dL) is normal. In children, a normal ionized calcium level is 4.8 to 5.52 mg/dL.
