A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
QuestAssureD™ 25-Hydroxy and Calcitriol 1,25-Dihydroxyvitamin D
Test Code16761
CPT Codes
82306, 82652
Includes
QuestAssureD™ 25-Hydroxyvitamin D (D2, D3) and Calcitriol 1,25-Dihydroxyvitamin D
Preferred Specimen
1.2 mL serum
Patient Preparation
Fasting preferred, but not required
Minimum Volume
0.6 mL
Instructions
Collect blood in a red-top tube (no gel) (preferred) or serum separator tube. Allow blood to clot (30 minutes) at room temperature. Centrifuge and separate the serum from the cells and transfer serum to a clean transport tube.
Transport Container
Transport tube
Transport Temperature
Room temperature
Specimen Stability
Room temperature: 21 days
Refrigerated: 21 days
Frozen: 21 days
Refrigerated: 21 days
Frozen: 21 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Grossly lipemic • Grossly icteric • Heparinized or EDTA plasma • Serum not separated from serum separtor tube gel or clot within 48 hours
Methodology
Chromatography/Mass Spectrometry
Setup Schedule
Set up: Mon-Sat; Report available: 2-3 days
Reference Range
QuestAssureD™ 25-Hydroxyvitamin D (D2, D3)
25-OHD3 indicates both endogenous production and supplementation. 25-OHD2 is an indicator of exogenous sources, such as diet or supplementation. Therapy is based on measurement of Total 25-OHD, with levels <20 ng/mL indicative of Vitamin D deficiency, while levels between 20 ng/mL and 30 ng/mL suggest insufficiency. Optimal levels are ≥30 ng/mL.
Calcitriol 1,25-Dihydroxyvitamin D
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.
Vitamin D, 25-OH, Total | 30-100 ng/mL |
Vitamin D, 25-OH, D3 | Not established |
Vitamin D, 25-OH, D2 | Not established |
Calcitriol 1,25-Dihydroxyvitamin D
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 |
Clinical Significance
Vitamin D originating from dietary and endogenous sources is converted to 25-hydroxyvitamin D in the liver, and subsequently to 1, 25-dihydroxyvitamin D in the kidney. Measurement of both the 1, 25-Dihydroxy and 25-Hydroxy forms provide insights into a variety of medical conditions such Vitamin D status in renal failure, differential diagnosis of primary, secondary and tertiary hyperparathyroidism. Differential diagnosis of hypercalcemia and type I and II inherited rickets.
Performing Laboratory
Quest Diagnostics Nichols Institute |
14225 Newbrook Drive |
Chantilly, VA 20153 |