UCSF Navigation Bar

UCSF Departments of Pathology & Laboratory Medicine Home Page

Lab Manual for UCSF Clinical Laboratories

Lab Manual for SFGH

Internal Resources

Click here for more information about laboratory operations and procedures

If you have additional questions regarding this test, please call: 415-353-1667

Search Our Test Menu

Calcium, total, Plasma / Serum

Item Value
Approval req'd? No
Available Stat? Yes
Test code CA
Test group Calcium
Performed by Parnassus, Mission Bay & Mt. Zion Chemistry
In House Availability Test available 24 hours per day 7 days per week
Method Ion selective electrode (ISE)
Container type Light green top preferred, Gold top acceptable
Amount to Collect 1 mL blood
Click here for Microdetermination info
Sample type Plasma or serum
Preferred volume 0.5 mL plasma or serum
Min. Volume 0.2 mL plasma or serum
Click here for Microdetermination info
Units mg/dL
Normal range
< 1 year 9.0-10.9 mg/dL
≥ 1 year 8.8-10.3 mg/dL

1. Normal range for children 0-1 year adopted from Beckman Coulter's "Pediatric Reference Range Guidelines for Synchron Systems" Bulletin 9345
2. Normal range for adults used for children >1 year. Beckman Coulter's "Pediatric Reference Range Guidelines for Synchron Systems" Bulletin 9345 for 1-3 year olds and Tietz', "Fundamentals of Clinical Chemistry" 5th ed, 2001, for 2-12 year olds showed reference intervals comparable to adult range.
3. Normal range for adults was determined by testing 270 male and female healthy blood donors at UCSF.
Critical value < 6.5 mg/dL or > 13.5 mg/dL
Synonyms Ca; Ca++
Stability Room temperature 8 hours, refrigerated 2 days, frozen at -20C 1 week
Turn around times STAT 1 hour, Routine 4 hours
Additional information To convert mg/dL to mmol/L (SI units) multiply by 0.25

A value < 4 or > 15 will automatically be reassayed

Gadolinium MR contrast agents including Gadodiamide (Omniscan), Gadoversetamide (Optimark), Gadopentetate Dimeglumine (Magnevist), and Gadoterdiol (Prohance), have been shown to interfere with certain colorimetric assays used in the measurement of various serum cations including iron, magnesium, and calcium. The UCSF clinical labs use electrode methods for measurement of total and ionized calcium levels which have not been reported to be subject to the gadolinium interference.

Reference:Proctor et al. Gadolinium Magnetic Resonance contrast Agents produce Analytic Interference in Multiple Serum Assays. Am J Clin Pathol. 2004;121:282-292.
CPT coding 82310
LOINC code 17861-6
Last Updated 8/6/2015 7:35:01 AM
Entry Number 161
Lab Procedure Link Click here for Procedure
UCSF home page UCSF home page About UCSF Search UCSF UCSF Medical Center