Test Overview

Test Methodology


Test Usage

Ionized calcium is the physiologically active form of calcium and a better indicator than total calcium of the functional status of calcium metabolism.

Reference Range*

1.12 - 1.30 mmol/L

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Details

Days Test Performed

Daily, 24 hours

Analytic Time

2 hours

Soft Order Code


MiChart Code

Calcium, Ionized



Free Calcium
Ionized Calcium

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Chemical Pathology

STAT Availability

STAT requests for this test will be performed on a STAT basis (supervisory staff approval is not required).

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Find a Requisition

All specimens should be accompanied by a requisition.

Submitting Specimens

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Test FAQ

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Specimen Requirements

Offsite Collection Instructions

Collect specimen in SST (preferred) or green top tube. Do not aliquot serum or remove stopper for any reason. Centrifuge and refrigerate intact specimen.

Rejection Criteria

Other Rejected Containers: Open Containers, EDTA plasma (lavender)


Yellow Top Tube

Normal Volume

2 mL serum

Minimum Volume

0.3 mL serum

Billing Information

Fee Codes

CPT Code




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