Calcium in Serum or Plasma (Mass Concentration)
This test measures the amount of calcium present in your blood, which is important for maintaining healthy bones, muscles, and nerves.
["Blood calcium levels help assess bone health and nerve function."]
Key facts at a glance
- LOINC
- 47369-4
- Short code
- CALC-BF
- Synonyms
- Calcit Fld-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top serum tube or serum separator tube (SST)
- Units
- N/A
- Ref low
- 0
- Ref high
- 11.5
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Chemiluminescent Immunoassay (CLIA)
- CPT
- 82308
- SNOMED
- 39579005
- Specimen volume
- 1-2 mL of serum
- Stability
- Stable for 8 hours at room temperature; refrigerated (2-8°C) for up to 48 hours; frozen (-20°C or below) for up to 3 months. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 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 cause symptoms such as muscle cramps, weakness, or irregular heartbeats. It may also be used to monitor conditions like kidney disease, osteoporosis, or certain cancers that affect calcium metabolism.
What to Expect Before the Test
No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it involves drawing blood from a vein, but this is not always required. Bring any medications or supplements you’re taking, as they can affect results.
What Happens During the Test?
A healthcare professional 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 significant discomfort. The blood sample is then sent to a lab for analysis.
What Are Possible Results?
Results are typically reported in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L). Your provider will interpret the results in relation to your overall health and symptoms.
Reference range
Reference ranges vary by laboratory, assay methodology, and specimen type. For serum: Male: <11.5 pg/mL; Female: <4.6 pg/mL. For body fluid values, interpret in clinical context.N/A
No special patient preparation required. Some clinicians may prefer a fasting sample to minimize interference from recent food intake.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Serum/Plasma Calcium
Frequently asked questions
What causes low calcium levels?
What causes high calcium levels?
How often should I get 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 16, 2026. · Read our editorial policy