Calcium in Serum (Mass Concentration)
This test measures the amount of calcium present in your blood serum, an important mineral that helps maintain strong bones, healthy nerves, and proper muscle function.
["Your blood calcium levels help your body stay strong and function normally."]
Key facts at a glance
- LOINC
- 58892-1
- Short code
- CALB
- Synonyms
- Calcit BS SerPl-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube; plasma may be collected in EDTA or heparin tubes
- Units
- N/A
- Ref low
- 0
- Ref high
- 11.5
- Critical range
- — – 100 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunoassay (Chemiluminescent or ELISA)
- CPT
- 82308
- SNOMED
- 1002541000009103
- Specimen volume
- 1.0 mL serum or plasma
- Stability
- Room temperature: 8 hours; Refrigerated (2-8°C): 24 hours; Frozen (-20°C or lower): 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 500
- Icterus max
- 25
- TAT
- 24–72 hours
- Order
- routine
Why Is This Test Done?
Doctors may order a serum calcium test to check for conditions like low or high calcium levels, which can cause symptoms such as muscle cramps, bone pain, or irregular heartbeat. It’s also used to diagnose or monitor diseases like kidney problems, osteoporosis, or certain cancers.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if it’s part of a broader metabolic panel. Bring any medications you’re taking to your doctor’s office.
During the Test
A healthcare provider will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but it usually doesn’t cause discomfort. The blood sample is then sent to a lab for analysis.
Possible Results and Next Steps
Results are typically reported in milligrams per deciliter (mg/dL). If your levels are outside the normal range, your doctor may recommend further testing or treatments, such as dietary changes, supplements, or medications.
Reference range
Males: <11.5 pg/mL; Females: <4.6 pg/mL (values may vary by assay method and laboratory)N/A
No special preparation required. For stimulation testing, refer to calcium or pentagastrin stimulation protocols. Patient should be informed about the purpose of baseline testing prior to possible thyroid surgery or evaluation of thyroid nodules.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
Serum Calcium
Frequently asked questions
What Does an Abnormal Result Mean?
How Often Should I Get This Test?
Can I Avoid This Test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 15, 2026. · Read our editorial policy