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St. John Health System
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Vitamin D, 25-Hydroxy Total (Vit D 25-OH)

Order Name VITAMIN D
Test Number: 3604940
Revision Date 07/20/2009
Test Name Methodology LOINC Code
Vitamin D, 25-Hydroxy Total (Vit D 25-OH)
Chemiluminescence Assay  
SPECIMEN REQUIREMENTS
Specimen Specimen Volume (min) Specimen Type Specimen Container Transport Environment
Preferred 1 mL (0.3) Serum Clot Activator SST Frozen
Alternate 1 1 mL (0.3) Plasma EDTA (Lavender Top) Frozen
Instructions Stability: After separation from cells: Ambient: 3 days; Refrigerated: 7 days; Frozen: 6 months.
*(Note: If ordering both Vitamin D 25OH & Vitamin D 1-25OH then seperate serum into two seperate aliquots and freeze. See collection instructions for Vitamin D 1-25 Dihydroxy.)
EDTA and Heparin Plasma is also acceptable.
GENERAL INFORMATION
Testing Schedule Sun-Sat 
Expected TAT 2-3 Days 
Clinical Use This assay accurately quantifies the sum of Vitamin D3 25-Hydroxy (the endogenous form) and Vitamin D2 25-Hydroxy (the supplement form). Optimum 25-hydroxy Vitamin D concentration is 35 ng/mL or higher. 
Notes Reports total Vitamin D, individual Vitamin D2 and D3 values will not be resulted as of October 16th, 2007.
CPT Code(s) 82306
Internal Comments old clinical data:Measurement of Vitamin D 25-OH (D2) is an indicator of compliance with supplements. Levels greater than 4 ng/mL suggest compliance. Vitamin D 25-OH (D3) indicates endogenous production. Therapy should be based on measurement of total Vitamin D 25-OH, with levels less than 20 ng/mL suggesting Vitamin D deficiency and levels between 20 ng/mL and 30 ng/mL suggesting a possible need for supplementation.
Service Provided By Labcorp Oklahoma, Inc.
Lab Section Reference Lab