Test Code LAB535 Vitamin D 25 Hydroxy
Performing Laboratory
Asante Rogue Regional Medical Center
Specimen Minimum Volume
0.3 mL
Billing Code
2071827
Methodology
Chemiluminescence
Specimen Requirements
Allow to clot and centrifuge ASAP after collection.
1.0 mL serum, SST or plain red top tube.
Day(s) Test Set Up
Performed daily Monday – Friday.
Test Classification and CPT Coding
82306 Vitamin D; 25 hydroxy, includes fraction(s), if performed
Additional Information
Use: The role of Vitamin D in bone and mineral
metabolism
was recognized from its first identification as a factor that
could
cure rickets. However, Vitamin D is now recognized as a
prohormone that has multiple roles in maintaining optimal
health. Vitamin D3 (cholecalciferol) and Vitamin D2
(ergocalciferol) are the most abundant forms of Vitamin D in
the
body. Vitamin D3 is synthesized in the skin from
7-dehydrocholesterol in response to sunlight. The best
nutrition sources of D3 are oily fish, primarily salmon and
mackerel. Vitamin D2’s nutrition sources are from
some
vegetables, yeast and fungi. The vegetarian diet is
abundant
in Vitamin D2.
Total vitamin D (D2 and D3 expressed as a total result)
Vitamin D Status |
25(OH) Vitamin D Concentration Range (ng/mL) |
Deficient |
< 20 |
Insufficient |
20 to < 30 |
Sufficient |
30 to 100 |
Toxic Level |
> 100 |
Specimen Transport Temperature and Stability
Centrifuge within 2 hours of collection. Stable 3 days room temp. 7 days 2-8 C. Freeze if testing delayed.
Performing Department
Chemistry
Reasons for Rejection
For assays employing antibodies, the possibility exists for interference by heterophile antibodies in the patient sample. Patients who have been regularly exposed to animals or have received immunotherapy or diagnostic procedures utilizing immunoglobulins or immunoglobulin fragments may produce antibodies, e.g., HAMA, that interfere with immunoassays. Additionally, other heterophile antibodies (e.g., human anti-sheep antibodies) may be present in patient samples. Such interfering antibodies may cause erroneous results. Carefully evaluate the results of patients suspected of having these antibodies.