Calcitriol 1,25‑Dihydroxyvitamin D
Use
1,25‑Dihydroxyvitamin D (calcitriol) is the biologically active form of vitamin D, playing a key role in regulating calcium and phosphorus metabolism, enhancing renal reabsorption of these minerals, promoting intestinal calcium absorption, and influencing bone and mineral homeostasis.
Special Instructions
Test is a Quest Diagnostics send‑out (referral) assay, now performed at MedFusion in Lewisville, Texas, as of November 21, 2022.
Limitations
Serum 1,25‑dihydroxyvitamin D does not reflect vitamin D stores and is not useful for routine assessment of vitamin D status; measurement is indicated only in disorders of 25(OH)D and phosphate metabolism, such as chronic kidney disease, hereditary phosphate‑wasting disorders, granulomatous diseases, and certain rickets syndromes.
New York Approved
Methodology
Immunoassay (Other)
Biomarkers
Result Turnaround Time
5-7 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
5.0 mL preferred; 1.5 mL minimum
Minimum Volume
1.5 mL
Container
Gold top (clot activator with gel) or red top (no anticoagulant)
Collection Instructions
Centrifuge, aliquot serum into plastic vial, freeze specimen
Patient Preparation
4‑hour fast preferred
Storage Instructions
Freeze specimen; transport frozen on dry ice
Causes for Rejection
Hemolysis, gross lipemia, EDTA plasma
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days |
Other tests from different labs that may be relevant