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Serum Calcium (Total)

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

This test measures the amount of calcium in your blood serum, which is important for maintaining healthy bones, muscles, and nerves.

Quick summary

["Calcium levels help your body function properly, including muscle contractions and nerve signaling."]

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

Key facts at a glance

LOINC
36555-1
Short code
XR Clavicle 1V
Synonyms
XR Clavicle 1V
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
xr
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?

Your healthcare provider may order this test to check for conditions like low or high calcium levels, which can affect bone health, heart function, or kidney issues. It might also be used to monitor certain medications or treatments that influence calcium balance.

What to Expect Before the Test

No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw blood, and you can eat and drink normally beforehand.

What the Results Mean

Results are typically reported as a numerical value, but your doctor will interpret them in relation to your overall health and symptoms. Abnormal levels may indicate conditions like hypocalcemia (low calcium) or hypercalcemia (high calcium).

Common Conditions Monitored

This test is often used to diagnose or monitor conditions such as osteoporosis, kidney disease, vitamin D deficiency, or certain cancers that may affect calcium metabolism.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Total Serum Calcium

Frequently asked questions

What causes abnormal calcium levels?
Abnormal calcium levels can result from conditions like kidney disease, thyroid disorders, bone diseases, or certain medications. It can also be influenced by dietary factors, vitamin D levels, or metabolic processes.
How often should I get this test?
The frequency depends on your health status and medical needs. Your doctor will determine how often you need this test based on your symptoms, medical history, and other tests.
Can diet affect my calcium test results?
Yes, diet can influence calcium levels. High intake of calcium-rich foods or supplements may temporarily affect test results, so it’s best to avoid large changes in diet before testing.
  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