Clinics and Departments

Laboratory Services

Lab Dept:


Test Name:


General Information

Lab Order Codes:



Calcium, Ionized, Blood, Ionized Calcium

CPT Codes:

82330 – Calcium, ionized

Test Includes:

Ionized calcium concentrations reported in mEq/L.


Test Indications:

Calcium in the fifth most common element and the most prevalent cation found in the body. Calcium exists in three physiochemical states in plasma, free/ionized, bound and complexed with small anions. Ionized calcium is a more useful measure than total calcium and provides the best indication of calcium status because it is biologically active and is tightly regulated by hormones. Calcium is used for the assessment and treatment of parathyroid disease, a variety of bone diseases and chronic renal disease.

Lab Testing Sections:


Phone Numbers:

MIN Lab: 612-813-6280

STP Lab: 651-220-6550

Test Availability:

Daily, 24 hours

Turnaround Time:

30 minutes

Special Instructions:

See Container for special container recommendations. See Collection for special draw requirements.


Specimen Type:

Whole blood


Preferred: Sims Portex syringe (PB151) or Smooth-E syringe (956-463) Accepted: Radiometer Balanced Heparin Capillary gas tubes

Draw Volume:

0.4 mL (Minimum: 0.2 mL syringe, 0.1 mL capillary) blood

Processed Volume:

0.2 mL syringe blood, 0.1 mL capillary blood


Routine venipuncture using one of the collection containers listed above. Immediately remove all air from syringe, remove needle, cap tightly, and mix. Send in original tube. Forward immediately at ambient temperature. Do not expose specimen to air.

Special Processing:

Lab Staff: Deliver ICA syringe/cap gas tube immediately to the lab testing station. Specimen should be analyzed within 2 hours of collection.

Patient Preparation:


Sample Rejection:

Mislabeled or unlabelled specimens; samples containing air; samples collected in containers other than balanced heparin; specimens older than 2 hours; clotted samples


Reference Range:



0 - 7 days:

2.10 - 2.96 mEq/L

8 days - 17 years:

2.40 - 2.76 mEq/L

>18 years:

2.32 - 2.64 mEq/L

Critical Values:

<1.50 mEq/L




Ion-Selective Electrode (ISE)


ALB800 FLEX Operator’s Manual from software version 6.04, Publication: 201011, Edition M, Code# 990-315,

Jacobs & DeMott Laboratory Test Handbook (2001) Lexi-Comp, Inc, Hudson, OH, 5th Edition

Tietz Textbook of Clinical Chemistry (1999) 3rd edition, WB Saunders Company


2/17/2005: Critical Value previously listed as <2.00 mEq/L.
10/13/2014: Stability on ice changed from 30 minutes to 2 hours.

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