Calcium (Ionized / Total)

Clinical definition of the calcium test
Calcium test measures the amount of calcium in the blood or urine. Calcium is one of the most important minerals in the body. It is essential for the proper functioning of muscles, nerves, and the heart and is required in blood clotting and in the formation of bones. About 99% of calcium is found in the bones while the remaining 1% circulates in the blood. Roughly half of the calcium in the blood is "free" and is metabolically active. The remaining half is "bound" to albumin and other compounds and is metabolically inactive. Calcium is lost from the body every day, filtered from the blood by the kidneys and excreted into the urine. Measurement of the amount of calcium in the urine is used to determine how much calcium is being eliminated by the kidneys.

Why is the calcium test done?
The calcium test is done to determine the levels of calcium in the blood and to screen for, diagnose and monitor a range of conditions relating to the bones, heart, nerves, kidneys and teeth.

What are the common signs/symptoms when the calcium test is done?

  • Fatigue
  • Weakness
  • Loss of appetite
  • Nausea
  • Vomiting
  • Constipation
  • Abdominal pain
  • Urinary frequency
  • Increased thirst
  • Abdominal cramps
  • Muscle cramps
  • Tingling fingers
  • Sharp pain in the side or back in the area of the kidneys
  • Pain in the lower abdomen
  • Blood in the urine

Who should do the calcium test (Target population)?

Persons showing the above signs & symptoms and those that suggest:

  • Kidney stones
  • Bone disease
  • Neurologic disorders
  • Person who has certain kinds of cancer (particularly breast, lung, head and neck, kidney and multiple myeloma), kidney disease, or has had a kidney transplant

What should I do before the calcium test?

Specimen type

Specimen collection procedure

Preparatory instructions before the test *


(Blood Sample)


(Collection of blood from a vein, usually from the arm)

No special preparations required.

*Subjects suffering from any illness or on oral or injectable medications are advised to consult their physician prior to requesting any tests or procedures.

How do I interpret my calcium test results?

Reference Range*


8.1 – 10.4 mg/dl


‘*A Reference range is a set of values which helps the healthcare professional to interpret a medical test. It may vary with age, gender, and other factors. Reference ranges may also vary between labs, in value & units depending on instruments used and method of establishment of reference ranges’

Diseases/conditions related to the calcium test

  • Kidney stones
  • Thyroid Disease
  • Intestinal disease
  • Malnutrition
  • Kidney disease
  • Kidney transplant
  • Certain kinds of cancer (particularly breast, lung, head and neck, kidney, and multiple myeloma)

Other tests related to the calcium test

  • Phosphorus
  • Vitamin D
  • Parathyroid hormone (PTH)
  • Magnesium
  • Albumin
  • Comprehensive metabolic panel (CMP)
  • Basic metabolic panel (BMP)

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Calcium (Serum)