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Serum or plasma mass concentration of calcium (total)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of calcium in your blood, which is important for many body functions, including muscle and nerve activity, bone health, and blood clotting.

Quick summary

["Your blood calcium levels help ensure your body stays strong and functions properly."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
23259-5
Short code
M cap capric Ab Ser Ql
Synonyms
M cap capric Ab Ser Ql
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Doctors may order this test to check for conditions affecting calcium balance, such as hypercalcemia (too much calcium) or hypocalcemia (too little calcium). It can also be used to monitor conditions like kidney disease, bone disorders, or certain cancers that may alter calcium levels.

What to Expect Before the Test

No special preparation is needed for this test. You may have a small needle inserted into a vein in your arm, and a blood sample will be drawn. If you’re on blood thinners or have a history of bleeding issues, let your healthcare provider know.

What to Expect During the Test

The test is quick and usually done in a clinic or lab. You may feel a slight pinch when the needle is inserted, but it should only last a few seconds. The blood sample is then sent to a lab for analysis.

What the Results Mean

Results are compared to standard reference ranges, but they can vary slightly depending on the lab. High or low calcium levels may signal underlying health issues that need further evaluation, such as thyroid problems, vitamin D deficiency, or kidney disease.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Total Calcium

Frequently asked questions

What are the normal reference ranges for this test?
Normal reference ranges can vary by lab and may include values like 8.5 to 10.2 mg/dL for total calcium in serum or plasma. Your doctor will interpret results based on your specific health needs and medical history.
How often should I get this test?
The frequency depends on your health condition. Some people may need this test yearly, while others may require it more often if they have ongoing health concerns like kidney disease or bone disorders.
Can diet affect calcium test results?
Yes, diet can influence calcium levels. High intake of calcium-rich foods (like dairy, leafy greens, or fortified foods) or certain medications (like vitamin D supplements) may temporarily affect results. Avoiding calcium supplements 24 hours before the test can help ensure accurate results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy