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Synonyms/Also Known as

Total Calcium, Ionized Calcium

Related tests

Phosphorus, Vitamin D Tests, PTH, Magnesium, Albumin

Why get tested?

To screen, diagnose and monitor therapy of calcium deficiency or excess.

When to get tested?

When there are symptoms related to kidneys, bones, thyroid, parathyroid, or nerves or when there are symptoms of increased or decreased calcium concentrations, in critically ill patients, to monitor ionized calcium levels when someone is treated for abnormal calcium levels and to monitor treatment.

Sample required


Test preparation needed

No special preparation required

About The Test

How is it used
Serum calcium test is done to screen, diagnose and monitor conditions that are related to bones, kidneys, teeth, heart and nerves, . The test is also done if there are symptoms of a parathyroid disorder, malabsorption, or hyperactive thyroid. An abnormal total calcium level needs additional tests such as ionized calcium, urine calcium, Phosphorus, Magnesium, vitamin D, parathyroid hormone (PTH) and PTH-related peptide to diagnose the underlying disorder as PTH and vitamin D are responsible for maintaining normal calcium levels in the blood. Serum calcium and PTH together can help to determine if the parathyroid glands are functioning normally. urine calcium levels help to determine if the kidneys are excreting the proper amount of calcium. Serum calcium can be used as a diagnostic test in Kidney stones, Bone disease and Neurologic disorders The total calcium test is the reflection of the amount of free calcium present in the blood since there is a stable balance between free and bound calcium. However, ionised calcium is measured when the balance between bound and free calcium is disturbed (critically ill patients, blood transfusions or intravenous fluids, major surgery, and low Albumin). Abnormal ionized calcium levels can cause the increase or decrease of heart rate, cause muscle spasm (tetany), and confusion or even coma.


What foods are rich in calcium?

Dairy products, eggs, green leafy vegetables, broccoli, legumes, nuts, and whole grains.

What is albumin-corrected calcium?

In blood, half of the calcium is bound to albumin. An abnormally low level of albumin will increase the free calcium level in the blood and vice versa. So an albumin-corrected calcium or adjusted calcium with a formula that uses the results of total calcium and albumin tests is used.