Calciumbldscnc
A blood calcium test measures the amount of calcium in your blood to evaluate bone health, nerve function, and heart health.
{"Measures calcium levels in your blood sample","Helps diagnose bone diseases, nerve problems, and heart conditions","Usually requires fasting for 8-12 hours before the test","Abnormal results may indicate kidney disease, parathyroid disorders, or vitamin D deficiency","The test is simple, low-risk, and takes only a few minutes"}
Key facts at a glance
- LOINC
- 1996-8
- Short code
- CA
- Synonyms
- Calcium Bld-sCnc
- Category
- electrolyte
- Sample
- whole-blood
- Container
- Serum separator tube (SST) or lithium heparin tube
- Units
- not specified
- Ref low
- 2.15
- Ref high
- 2.55
- Critical range
- 1.5 not specified – 3.25 not specified
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 18 years
- Method
- Ion-selective electrode (ISE) or colorimetric Arsenazo III method
- CPT
- 82310
- SNOMED
- 271232006
- Specimen volume
- 1.0 mL serum or plasma minimum
- Stability
- Room temperature: 7 days; Refrigerated (2-8°C): 14 days; Frozen (-20°C): 3 months
- Hemolysis max
- 50
- Lipemia max
- 300
- Icterus max
- 20
- TAT
- 1–4 hours
- Order
- routine
What is a Blood Calcium Test?
A blood calcium test, also called a serum calcium test, measures the concentration of calcium in your blood. Calcium is a vital mineral that plays a key role in bone health, muscle contraction, nerve signal transmission, and heart function. This test helps your healthcare provider evaluate how well your body is regulating calcium levels.
Why Do I Need This Test?
Your doctor may order a blood calcium test to: check for bone diseases like osteoporosis; evaluate kidney function since kidneys help regulate calcium; diagnose parathyroid gland disorders; monitor people with cancer, especially those undergoing treatment; investigate symptoms like muscle cramps, fatigue, or irregular heartbeats; and monitor calcium levels if you take calcium or vitamin D supplements.
How Do I Prepare for the Test?
Follow these preparation guidelines: fasting is usually required for 8-12 hours before the test, though your doctor may allow water; inform your doctor about all medications you're taking, including supplements, as some can affect results; avoid taking calcium supplements on the day of the test unless directed otherwise; tell your doctor if you are pregnant, as pregnancy can affect calcium levels; and rest and avoid strenuous exercise before the test as physical activity can temporarily change calcium levels.
What Happens During the Test?
During the test, a healthcare professional will: clean the inside of your elbow or the back of your hand with an antiseptic wipe; wrap an elastic band around your upper arm to make your veins more visible; insert a needle into a vein and collect blood into a vial or tube; apply pressure to the puncture site to stop bleeding; and place a bandage over the site. The procedure takes only a few minutes and may cause minor discomfort or bruising.
Understanding Your Results
Normal blood calcium levels typically range from 8.5 to 10.5 mg/dL (2.12 to 2.62 mmol/L). Your exact normal range may vary slightly depending on the laboratory. Results outside this range may require additional testing to determine the cause. Your doctor will interpret your results based on your overall health, symptoms, and other test findings.
Reference range
2.15-2.55 mmol/Lnot specified
No special preparation or fasting usually required
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings3
Frequently asked questions
Does the blood calcium test hurt?
How long does it take to get results?
Do I need to fast before a calcium blood test?
What can affect my calcium test results?
Is a calcium test different from a bone density test?
Sources
- 1
- 2
- 3
- 4
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 10, 2026. · Read our editorial policy