Before this test, consult with your health care provider about the need to withhold drugs that can affect the test. The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. How the Test will Feel When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing. Measurement of the serum calcium level is useful for determining the cause of kidney or thyroid problems and if an appropriate amount of vitamin D in the person's body.
All cells require calcium for numerous functions.
Calcium is especially important in the structure of bones and in neuromuscular activity. About half of the calcium in the serum is loosely associated with proteins . The accuracy of this method depends on having normal amounts of binding proteins. If the levels of binding proteins are increased or decreased, the amount of serum calcium will appear to be increased or decreased, because it is the free calcium that is regulated hormonally by the body. In these circumstances, ionized calcium is a more reliable measure of calcium levels.