Vitamin D, 1,25-Dihydroxy

Test Code
VITD(1,25) (16558)

Quest Code

CPT Codes

Vitamin D,1,25 (OH)2,Total
Vitamin D3, 1,25 (OH)2
Vitamin D2, 1,25 (OH)2

Preferred Specimen
1 mL serum

Minimum Volume
0.5 mL

Collect blood in a non-gel barrier red-top tube. Allow blood to clot (30 minutes) at room temperature. Centrifuge and separate the serum from the cells.

Note: If sample is submitted with less than 1.1 mL and needs to be repeated, the sample will be canceled with the comment TNP-Initial testing necessitated a repeat, but there was insufficient sample to perform repeat.

Transport Temperature
Room temperature

Specimen Stability
Room temperature: 28 days
Refrigerated: 28 days
Frozen: 28 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Lipemia • Icteric specimens • Plasma

Chromatography/Mass Spectrometry

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Report Available
3 to 3 Day(s)

Reference Range
Vitamin D, 1,25 (OH)2, Total  
1-9 Years 31-87 pg/mL
10-13 Years 30-83 pg/mL
14-17 Years 19-83 pg/mL
Adult 18-72 pg/mL
Vitamin D3, 1,25 (OH)2 Not available
Vitamin D2, 1,25 (OH)2 Not available
Reference ranges are established for total 1,25-dihydroxy vitamin D. Values for subcomponents D2 (derived from plant or fungal sources) and D3 (derived from human or animal sources) are provided for informational purposes only.

Clinical Significance
This test measures the bioactive form of vitamin D. It is used in the differential diagnosis of hypocalcemia and to monitor patients with renal osteodystrophy or chronic renal failure. This test is not suitable for diagnosis of vitamin D deficiency and monitoring supplementation in most patients. The 25-hydroxyvitamin D test is the recommended test for those purposes (N Engl J Med. 2007;357:266-281).

Performing Laboratory
Quest Diagnostics Nichols Institute
27027 Tourney Road
Valencia, CA 91355-5386

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.