Serum or plasma mass concentration of calcium
This test measures the amount of calcium in your blood, which is important for many body functions, including muscle and nerve activity, as well as bone health.
["Checks calcium levels to prevent deficiencies or excesses that could affect your health."]
Key facts at a glance
- LOINC
- 26931-6
- Short code
- C4
- Synonyms
- C4 SerPl-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube; plasma acceptable in heparin or EDTA tubes
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunonephelometry or Immunoturbidimetry
- CPT
- 86160
- SNOMED
- 71878006
- Specimen volume
- 1 mL serum or plasma
- Stability
- Room temperature: 8 hours; Refrigerated (2-8°C): 2 days; Frozen (-20°C or below): 30 days
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test if you have symptoms like muscle cramps, numbness, fatigue, or bone pain. It may also be done to monitor conditions like kidney disease, osteoporosis, or certain metabolic disorders. Sometimes, it’s part of routine check-ups or to evaluate calcium-related medications.
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 a fasting sample. If you’re on calcium supplements or certain medications, let your provider know. Avoid drinking calcium-rich beverages like milk or juice before the test if instructed.
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 will be sent to a lab for analysis.
What Does the Test Result Mean?
Results are compared to standard ranges, but your specific reference values may vary based on lab methods and your healthcare provider’s guidelines. Low calcium levels (hypocalcemia) can cause weakness or spasms, while high levels (hypercalcemia) may lead to fatigue or kidney issues. Your provider will discuss results with you in detail.
Reference range
Adults: 10-40 mg/dL (may vary by laboratory and assay method)N/A
No special preparation required. Fasting is not necessary.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
Calcium Level
Frequently asked questions
How often do I need this test?
Can I eat or drink anything before the test?
What if my calcium level is too high or too low?
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