Calcitrol 1,25 -Dihydroxyvitamin D

Overview

  • EPIC Code:
  • LAB536
  • Soft Test Code:
  • VITD2
  • Send Out Test Code:
  • 16558
Alternate Names
  • 1, 25-Dihydroxyvitamin D
  • Calcitrol Level
  • Vit D1, 25 Dihydroxy
  • Vitamin D 1, 25 Dihydroxy
  • Vitamin D-1, 25
  • Vitamin D, 1,25-Dihydroxy, LC/MS/MS
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).   25-OH Vitamin D level is performed by PHL and should be ordered as test code VD251.  1,25-dihydroxy Vitamin D is performed by Quest Diagnostics and should be ordered as test code VITD2.


Specimen Collection & Preparation

Specimen Requirements:

-OR-

2.0 mL Serum in a SST Gold Top Tube 
Minimum Volume:
1.1 mL Serum*

* This volume does not allow for repeat testing

Collection Instructions:

Avoid Hemolysis


Processing Instructions:

1. Allow blood to clot (30 minutes) at ambient temperature
2. Centrifuge and separate the serum from the cells.


Rejection Criteria:

Grossly hemolyzed; Lipemic; Icteric specimens; Plasma 


Clinical Interpretation

Reference Range:

Vitamin D3, 1,25(OH)2:

   No age/sex specific ranges for this test.

Vitamin D2, 1,25(OH)2:

   No age/sex specific ranges for this test.

Vitamin D, 1,25(OH)2, Total, LC/MS/MS:

   1 year to 9 years: 31-87 pg/mL

   10 years to 13 years: 30-83 pg/mL

   14 years to 17 years: 19-83 pg/mL

   Adults: 18-72 pg/mL 

Vitamin D3, 1,25(OH)2 indicates both endogenous production and supplementation.

Vitamin D2, 1,25(OH)2 is an indicator of exogenous sources, such as diet or supplementation.

Interpretation and therapy are based on measurement of Vitamin D, 1,25 (OH)2, Total.


Methodology:
  • Liquid Chromatography / Tandem Mass Spectrometry (LC-MS/MS)

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).   25-OH Vitamin D level is performed by PHL and should be ordered as test code VD251.  1,25-dihydroxy Vitamin D is performed by Quest Diagnostics and should be ordered as test code VITD2.


Production Schedule

Sites Performed
  • Quest - Chantilly
Days Performed
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Departments
  • Sendouts - Clinical
Turn Around Time

5 to 8 days


Coding & Compliance

CDM

01422846


CPT Coding

82652