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Test Code VITD  Vitamin D 25-Hydroxy, Total (D2 and D3), Serum

Important Note

Population based screening for deficiency of this vitamin is not indicated.

Vitamin D deficiency is common in many populations, particularly in patients at higher latitudes, during winter months and in those with limited sun exposure. Over the counter Vitamin D supplements and increased summer sun exposure are sufficient for most otherwise healthy patients. 

Laboratory testing is appropriate in higher risk patients when results will be used to institute more aggressive therapy (e.g., osteoporosis, chronic kidney disease, malabsorption, some infections, obese individuals).

Additional Codes

EPIC CODE

LAB2292

Performing Laboratory

Bronson Laboratory Services-Chemistry

 

Please note: At BMH, samples that yield values >120 ng/mL have the test code HDN25 auto-reflex ordered. The sample is given to sendouts for Vitamin D testing at Mayo by a LC/MS method. This sendout is done to confirm a potentially high or toxic level. This is done because there have been a few sporadic cases where an undetermined cross-reactivity has caused an apparent falsely elevated value for this test.

Reference Values

Deficient: <10 ng/mL

Insufficient: 10-29 ng/mL

Sufficient: 30-100 ng/mL

Potential intoxication: >100 ng/mL

Note: This assay measures total 25-hydroxy vitamin D, which consists of vitamin D2 and vitamin D3. Vitamin D2 is synthesized in plants and is present in some supplements.  Vitamin D3 is synthesized by exposure of skin to sunlight and is also present in the diet as well as in supplements.

 

 

Methodology

Chemiluminescent Enzyme Immunoassay

Specimen Requirements & Patient Preparation

Patient Preparation: For 12 hours before this test do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.   Biotin can interfere with many immunoassay tests.

 

Specimen Type: Serum

Container/Tube: Gold top serum gel or
plain red top

Specimen Volume: 1 mL

Specimen Minimum Volume: 0.5 mL

Collection Instructions: Spin down and
separate serum from cells as soon as possible after draw.

 

Alternate Specimen

5/4/18: A bulletin from the vendor recommends use of serum only. Other specimen types are not recommended

Specimen Transport Temperature

Ambient 3 days/Refrigerate 1 week/Frozen 3 months

Day(s) Test Set Up

Daily,  24/7

Test Classification and CPT Coding

82306