Calcium Blood Test

What is a calcium blood test?

A calcium blood test measures the level of calcium in your blood.

There are two types of calcium blood tests:

• Total calcium. This test measures the calcium attached to certain proteins in your blood and “free” (unattached) calcium.
• Ionized calcium. This test measures the calcium that’s unattached from certain proteins in your blood.

Calcium is one of the most important and common minerals in your body. About 99% of your body’s calcium is in your bones and teeth. The other 1% of it is in your blood.

A calcium blood test can’t show how much calcium is in your bones. Your healthcare provider can check your bone health with a bone density test (DEXA scan).

Why do I need a calcium blood test?

You may need a calcium blood test for one of four reasons:

• You’re getting routine bloodwork called a basic metabolic panel (BMP)or comprehensive metabolic panel (CMP). These both measure blood calcium.
• You have symptoms of too much calcium (hypercalcemia) or too little calcium (hypocalcemia) in your blood.
• You have a condition that affects your blood calcium level, so your provider wants to check if your treatment is working.
• You take a medication that affects your blood calcium levels, so you need routine tests to monitor your levels.

How do I prepare for a calcium blood test?

You don’t need to follow any special instructions before a calcium blood test if it’s your only test.

The test may be part of a basic or comprehensive metabolic panel. These tests measure multiple substances in your blood. In this case, you may need to not eat or drink (fast) for several hours before your blood draw. Your healthcare provider will let you know if you need to follow any special instructions.

What can I expect during a calcium blood test?

You can expect to experience the following during a blood test, or blood draw:

1. You’ll sit in a chair. A healthcare provider (usually a phlebotomist) will check your arms for an easily accessible vein. This is usually in the inner part of your arm on the other side of your elbow.
2. Once they’ve located a vein, they’ll clean and disinfect the area.
3. They’ll then insert a small needle into your vein to take a blood sample. This may feel like a small pinch.
4. After they insert the needle, a small amount of blood will collect in a test tube.
5. Once they have enough blood to test, they’ll remove the needle. They’ll hold a cotton ball or gauze on the site to stop the bleeding.
6. They’ll place a bandage over the site, and you’ll be finished.

The entire procedure usually takes less than five minutes.

When should I get my test results?

In most cases, you should have your test results within one or two days, though it could take longer.

After the phlebotomist has collected your blood sample, they’ll send it to a laboratory for testing. Once the test results are back, your healthcare provider will share the results with you.

What do the results of a calcium blood test mean?

Blood test reports, including calcium blood test reports, usually provide:

• The name of the blood test or what was measured in your blood
• The number or measurement of your blood test result
• The normal measurement range for that test
• Information that states if your result is normal or abnormal, or high or low

What are normal levels?

In most cases, a normal blood calcium level for adults is 8.5 to 10.2 milligrams/deciliter (2.15 to 2.55 millimoles/liter). But laboratories may have different reference ranges for normal blood calcium levels. You shouldn’t compare values from one laboratory to normal ranges from another laboratory.

When you get the results, there’ll be information that indicates what that lab’s normal blood calcium range is. If you have any questions about your results, be sure to ask your healthcare provider.

What does a high blood calcium level mean?

If your results reveal that you have higher-than-normal levels of calcium in your blood, you may have:

• Hyperparathyroidism
• Lung diseases like sarcoidosis and tuberculosis
• Kidney failure
• Lung cancer
• Breast cancer
• Certain blood cancers
• Hyperthyroidism
• Paget’s disease of the bone
• Multiple myeloma

It’s important to remember that a high calcium result doesn’t necessarily mean that you have a medical condition. Certain medications can also increase your blood calcium levels.

What does a low calcium blood level mean?

If your results reveal that you have lower-than-normal levels of calcium in your blood, you may have:

• Hypoparathyroidism
• Vitamin D deficiency
• Kidney failure
• Hypomagnesemia
• Pancreatitis
• Celiac disease or other conditions that cause malabsorption

A low calcium result doesn’t necessarily mean you have a medical condition. Certain medications and eating patterns can also decrease your blood calcium levels.

Should I be concerned if I have high or low blood calcium results?

If you have high or low blood calcium results, it doesn’t guarantee you have a medical condition. Other factors, like what you eat and certain medications, can affect your calcium levels. There could’ve also been an error in the collection, transport or processing of the test.

If you have an abnormal result, your healthcare provider may order more tests to find the cause of the abnormal levels. These tests may measure your:

• Ionized blood calcium
• Urine calcium
• Phosphorus
• Magnesium
• Vitamin D
• Parathyroid hormone
• Thyroid hormones
• Calcitonin

If you have questions about your results, don’t hesitate to ask your healthcare provider.

When should I call my healthcare provider?

If you have concerning symptoms of hypocalcemia or hypercalcemia, contact your healthcare provider as soon as possible.