VITAMIN D, 1,25 DIHYDROXY

Mnemonic

D1 25 OH

Synonym

Vitamin D – 1,25-Dihydroxyvitamin D2 – 1,25-Dihydroxyvitamin D3

Guidelines

May be useful for evaluating calcium metabolism in individuals with hypercalcemia or renal failure in addition to 25-Hydoxyvitamin D testing. Test is not appropriate for diagnosing vitamin D deficiency or insufficiency.

Specimen Collection Requirements

Collect

Serum, one 5.0 mL gold (SST) or 7.0 mL red top tube

Handling

Allow serum to clot completely at room temperature (minimum – SST: 30 minutes; red top tubes: 60 minutes). Centrifuge and separate serum from cells within 20 hours of collection.

 

Samples containing particulate matter, turbidity, lipemia, or erythrocyte debris may require clarification by centrifugation before testing.

Preferred Volume

1.0 mL Serum

Minimum Volume

0.5 mL Serum (1.2 mL minimum whole blood draw)

Transport

Refrigerated (2-8 C)

Rejection Criteria

Plasma, grossly hemolyzed samples, grossly lipemic samples, and samples frozen and thawed more than 4 times.

Stability

WHOLE BLOOD (UNSPUN): Room Temperature (18-26°C): 20 hours; Refrigerated (2-8°C): 20 hours; Frozen (≤-20°C): unacceptable

 

SERUM (SEPARATED FROM CELLS, POST COLLECTION): Room Temperature (18-26°C): 7 days; Refrigerated (2-8°C): 14 days; Frozen (≤-20°C): 6 weeks

Do not exceed 4 freeze-thaw cycles.

Testing Information

Performed

Monday and Thursday

Reported

1-4 days

Method

Diasorin Liaison XL Chemiluminescent Immunoassay

Reference Values

Reference Values

19.9-79.3 pg/mL

CPT Codes

82652

Last Updated: Thursday, January 17, 2019 09:24:16 AM