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Calcium, Total — With or Without Correction

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

Measures total calcium in a blood sample. Some reports also include an albumin-corrected calcium estimate.

Quick summary

["This test checks the amount of calcium in your blood and may adjust the result for your albumin level."]

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

Key facts at a glance

LOINC
83303-8
Short code
CT Toe WO contr
Synonyms
CT Toe WO contr
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

This blood test measures the total amount of calcium in your body fluids. Calcium is needed for bone health, muscle contraction, nerve function, and blood clotting.

Why might I need this test?

Your clinician may order it to evaluate calcium levels, investigate symptoms such as weakness, muscle cramps, numbness, confusion, or bone pain, or monitor certain illnesses and treatments.

How is the test performed?

A blood sample is collected and analyzed in the laboratory. If requested, the report may also include corrected calcium, which adjusts the total calcium result using the measured albumin level.

How do I prepare for the test?

Fasting is usually not required, but follow your clinician's instructions if the test is part of a larger panel. Tell the laboratory about calcium or vitamin D supplements, and do not change prescribed medicines unless instructed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

High total calcium may be associated with conditions such as an overactive parathyroid gland, excess vitamin D, certain tumors, or excessive calcium supplementation. Low total calcium may occur with vitamin D deficiency, kidney disease, malabsorption, or an underactive parathyroid gland. Albumin correction can help interpret results when albumin levels are abnormal, but abnormal results require clinical evaluation.

Short name

Total Calcium

Frequently asked questions

What is corrected calcium?
Corrected calcium is an estimate of calcium after accounting for the amount of albumin, a blood protein that carries calcium. The correction method can vary by laboratory.
Do I need to fast for this test?
Fasting is usually unnecessary unless your clinician specifically requests it. Follow the preparation instructions provided with your lab order.
What can affect my calcium result?
Calcium and vitamin D supplements, certain medicines, kidney function, parathyroid activity, and your albumin level can all influence the result.
  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