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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)

Reporting Name

25-Hydroxyvitamin D2 and D3, S

Specimen Type

Serum

Specimen Required

Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.5 mL

Specimen Minimum Volume

0.25 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 14 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

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

***Optimum levels in the healthy population; patients with bone disease may benefit from higher levels within this range

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

****80 ng/mL is the lowest reported level associated with toxicity in patients without primary hyperparathyroidism who have normal renal function. Most patients with toxicity have levels >150 ng/mL. Patients with renal 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.

Day(s) and Time(s) Performed

Monday through Friday; Continuous until 2:30 p.m.

Specimens on patients who are <1 year old are only performed on Tuesday and Friday.

Performing Laboratory

Mayo Medical 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 In Process

Test Classification

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

Forms

If not ordering electronically, complete, print, and send a General Request Form (T239) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/general-request-form.pdf).