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Test ID 25HDN 25-Hydroxyvitamin D2 and D3, Serum

Useful For

Diagnosis of vitamin D deficiency

 

Differential diagnosis of causes of rickets and osteomalacia

 

Monitoring vitamin D replacement therapy

 

Diagnosis of hypervitaminosis D

Method Name

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

 

Portions of this test are covered by patents held by Quest Diagnostics

Reporting Name

25-Hydroxyvitamin D2 and D3, S

Specimen Type

Serum


Specimen Required


Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial within 2 hours of specimen collection.


Specimen Minimum Volume

0.25 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 28 days
  Frozen  30 days
  Ambient  7 days

Reference Values

TOTAL 25-HYDROXYVITAMIN D2 AND D3 (25-OH-VitD)

<10 ng/mL (severe deficiency)*

10-19 ng/mL (mild to moderate deficiency)**

20-50 ng/mL (optimum levels)***

51-80 ng/mL (increased risk of hypercalciuria)****

>80 ng/mL (toxicity possible)*****

 

*Could be associated with osteomalacia or rickets

**Might be associated with increased risk of osteoporosis or secondary hyperparathyroidism

***Optimum levels in the healthy population

****Sustained levels >50 ng/mL 25OH-VitD along with prolonged calcium supplementation may lead to hypercalciuria and decreased kidney function

*****80 ng/mL is the lowest reported level associated with toxicity in patients without primary hyperparathyroidism who have normal kidney function. Most patients with toxicity have levels >150 ng/mL. Patients with kidney failure can have very high 25-OH-VitD levels without any signs of toxicity, as renal conversion to the active hormone 1,25-OH-VitD is impaired or absent.

 

These reference ranges represent clinical decision values, based on the 2011 Institute of Medicine report, that apply to males and females of all ages, rather than population-based reference values. Population reference ranges for 25-OH-VitD vary widely depending on ethnic background, age, geographic location of the studied populations, and the sampling season. Population-based ranges correlate poorly with serum 25-OH-VitD concentrations that are associated with biologically and clinically relevant vitamin D effects and are therefore of limited clinical value.

 

For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html.

Day(s) Performed

Monday through Friday

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

82306

LOINC Code Information

Test ID Test Order Name Order LOINC Value
25HDN 25-Hydroxyvitamin D2 and D3, S 49590-3

 

Result ID Test Result Name Result LOINC Value
2897 25-Hydroxy D2 49054-0
2898 25-Hydroxy D3 1989-3
83670 25-Hydroxy D Total 62292-8

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

Report Available

2 to 5 days

NY State Approved

Yes

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-General Request (T239)

-Renal Diagnostics Test Request (T830)