QuestAssureD 25-Hydroxy and Calcitriol 1,25-Dihydroxyvitamin D
Quest Diagnostics
Sample type: Serum
Requires fasting: No
Phlebotomy required
Details
QuestAssureD™ 25-Hydroxy and Calcitriol 1,25-Dihydroxyvitamin D - 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.
- Vitamin D, 25-OH, Total
- 25-OH Hydroxy Vitamin D (Cholecalciferol D3)
- 25-OH Hydroxy Vitamin D (Ergocalciferol D2)
- Vitamin D, 1,25 (OH)2, TOTAL
- Vitamin D2, 1,25 (OH)2
- Vitamin D3, 1,25 (OH)2
Estimated days for results: Results should be available in 2 - 5 business days after the sample is collected
2–5 business days
Vitamin D, 25-OH, Total 30–100 ng/mL
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.
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
Age Group Reference Range
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.
- Fasting before a blood draw means you don't eat or drink anything except water.
- Your doctor should provide any special instructions related to fasting for your test. Always follow your doctor's instructions.
Blood Draw Options with Fullscript
Fullscript offers several convenient phlebotomy options to complete your lab testing:
Quest Diagnostics Patient Service Centers (PSC)
- Location: Visit a nearby Quest Diagnostics Patient Service Center.
- Cost: $10 sample collection fee (paid during lab order checkout).
- Scheduling: Schedule your appointment here. Appointments are recommended to reduce wait times. Walk-ins are accepted, but may experience delays. Aim to arrive 10 minutes before your appointment.
- Collection Instructions:
- Bring a valid ID.
- Bring your digital or printed requisition form, available in the Labs tab of your Fullscript account.
- Check-in: Scan the QR code from your confirmation email or follow kiosk instructions.
- More Info: Quest Diagnostics blood draw guide
Getlabs Mobile Phlebotomy
- Location: Sample collection at your home or office.
- Cost: $85 sample collection fee (paid during lab order checkout).
- Availability: Available in most locations – enter your ZIP code during checkout to confirm.
- Scheduling: Schedule your appointment here through your Fullscript account.
- Collection Instructions:
- Have your digital or printed requisition form and valid ID ready.
- Your phlebotomist will contact you by phone to coordinate arrival.
- More Info: Getlabs blood draw guide
- Preferred Specimen(s): 2 mL serum
- Alternative: NA
- Minimum Volume: 1.2 mL
- Collection Instructions: NA
- Transport Container: Transport tube
- Transport Temperature: Room Temperature
- Specimen Stability:
- Room temperature: 21 days
- Refrigerated: 21 days
- Frozen: 21 days
- Reject Criteria:
- Gross hemolysis • Lipemia • Heparinized or EDTA plasma • Icteric • Serum not separated from serum separator tube (SST) gel or clot within 48 hours
State restrictions:
Patient can't order this test if they are located in Hawaii, Puerto Rico, New Jersey, New York, or Rhode Island
