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Calciumspecscnt

Published: July 31, 2026Updated: August 10, 2026

A blood test that measures the amount of calcium in your blood to evaluate bone health, kidney function, and nerve function.

Quick summary

{"This test measures calcium levels in your blood serum","It helps diagnose conditions affecting bones, kidneys, and nerves","Normal calcium levels are essential for proper muscle and heart function","Your doctor may order this test as part of routine blood work or if you have symptoms of abnormal calcium","The test requires a simple blood draw from a vein in your arm"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 10, 2026Editorial policy

Key facts at a glance

LOINC
53502-1
Short code
Ca
Synonyms
Calcium Spec-sCnt
Category
electrolyte
Sample
serum
Container
Serum separator tube (SST) or plain red top tube
Units
not specified
Ref low
8.5
Ref high
10.2
Critical range
6 not specified – 13 not specified
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
Colorimetric (Arsenazo III) or Ion-Selective Electrode (ISE)
CPT
82310
SNOMED
271055001
Specimen volume
1-2 mL serum
Stability
Room temperature: 48-72 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C): 30 days
Hemolysis max
50
Lipemia max
300
Icterus max
20
TAT
1–4 hours
Order
routine

What is this test?

The blood calcium test measures the amount of calcium in your blood. Calcium is an important mineral that your body needs for many functions, including building strong bones and teeth, helping muscles contract, regulating heart rhythm, and ensuring nerves transmit signals properly. This test uses a sample of your serum (the liquid part of your blood after it clots) to measure calcium levels.

Why is this test performed?

Your healthcare provider may order a calcium blood test for several reasons: to check your overall health as part of a routine metabolic panel, to monitor conditions that affect calcium levels such as kidney disease, parathyroid disorders, or osteoporosis, to evaluate symptoms like muscle cramps, weakness, fatigue, or irregular heartbeats, and to monitor the effectiveness of calcium or vitamin D supplements or medications.

How is the test performed?

A healthcare professional will draw a small sample of blood from a vein in your arm using a needle. The blood sample will be sent to a laboratory for analysis. The procedure is quick and usually takes only a few minutes. You may experience slight discomfort or a bruise at the needle site, but serious complications are rare.

How to prepare for the test?

In most cases, you do not need to fast before a calcium blood test unless your doctor instructs otherwise. However, certain medications and supplements can affect calcium levels, so inform your doctor about all medications you are taking. Stay well-hydrated before the test to make blood draw easier. If you have questions about your specific preparation instructions, consult your healthcare provider.

Reference range

8.5-10.2 mg/dLnot specified

Specimen: serum

No special preparation or fasting required

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

What are the normal calcium levels in blood?
Normal blood calcium levels typically range from 8.5 to 10.5 mg/dL (2.12 to 2.62 mmol/L). However, the exact normal range may vary slightly depending on the laboratory and testing methods used. Your doctor will explain what your specific results mean.
Does this test require fasting?
Typically, fasting is not required for a calcium blood test. However, follow any specific instructions your healthcare provider gives you, as they may have reasons to request fasting based on your individual situation.
What does it mean if my calcium is high?
High blood calcium (hypercalcemia) can be caused by overactive parathyroid glands (hyperparathyroidism), certain cancers, excessive vitamin D intake, kidney disease, or certain medications. Your doctor will perform additional tests to determine the cause and appropriate treatment.
What does it mean if my calcium is low?
Low blood calcium (hypocalcemia) can result from low parathyroid hormone (hypoparathyroidism), vitamin D deficiency, kidney problems, low magnesium levels, or certain medications. Treatment involves addressing the underlying cause and may include calcium and vitamin D supplements.
Can I take my calcium supplements before the test?
Inform your doctor about all supplements and medications you take before the test. Depending on your situation, your doctor may ask you to stop taking calcium or vitamin D supplements for a certain period before the test to get accurate results.
  1. 1
    MedlinePlus - Calcium Blood TestSource
  2. 2
    Mayo Clinic - Calcium Blood TestSource
  3. 3
    National Institutes of Health - CalciumSource

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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 10, 2026. · Read our editorial policy