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Serum or plasma concentration of calcium (total)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of calcium in your blood, which is important for keeping your bones strong, muscles working properly, and nerves functioning correctly.

Quick summary

["Your blood calcium levels help maintain healthy bones, muscle function, and nerve signals."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
44394-5
Short code
Kappa LC 24h Ur Ql
Synonyms
Kappa LC 24h Ur Ql
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your doctor may order this test to check for conditions like low or high calcium levels, which can cause symptoms such as muscle cramps, weakness, or unusual heart rhythms. It may also be done to monitor conditions like kidney disease, bone disorders, or certain cancers that affect calcium metabolism.

What Does the Test Involve?

A blood sample is taken from a vein in your arm. The sample is sent to a lab where it is analyzed to determine the total calcium concentration in your serum or plasma.

What Are Common Causes of Abnormal Results?

Low calcium levels (hypocalcemia) can occur due to conditions like vitamin D deficiency, kidney problems, or certain medications. High calcium levels (hypercalcemia) may result from overactive thyroid, bone diseases, or prolonged exposure to sunlight.

What Do the Results Mean?

Results are interpreted by your healthcare provider based on your overall health, symptoms, and other test results. Abnormal levels can indicate underlying health issues that need further evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Total Serum Calcium

Frequently asked questions

What does a total serum calcium test measure exactly?
This test measures the total amount of calcium (both ionized and protein-bound) in your blood serum or plasma. It does not differentiate between the free (ionized) calcium and the calcium bound to proteins like albumin.
How often should I get this test if I have no symptoms?
If you have no symptoms and no known conditions affecting calcium levels, your doctor may only recommend this test if there are other reasons to suspect calcium imbalance, such as family history or specific medical conditions.
Can diet affect the results of this test?
Yes, diet can influence calcium levels. Consuming too much calcium from supplements or foods, or deficiencies in vitamin D, can affect test results. It’s best to follow your doctor’s advice regarding timing and dietary considerations before the test.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

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 16, 2026. · Read our editorial policy