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Test ID B12 Vitamin B12 Assay, Serum

Useful For

Investigation of macrocytic anemia

 

Workup of deficiencies seen in megaloblastic anemias

Special Instructions

Method Name

Immunoenzymatic Assay

Reporting Name

Vitamin B12 Assay, S

Specimen Type

Serum


Ordering Guidance


Ask patients if they have received a vitamin B12 injection or radiolabeled vitamin B12 injection within the last 2 weeks. Patient results will not reflect deficiency or malabsorption after recent B12 injection. If patient has received such an injection within the past 2 weeks, this test should not be ordered.

 

This test provides a measurement of serum vitamin B12 level only. For a more comprehensive workup, order ACASM / Pernicious Anemia Cascade, Serum, which initiates testing with measurement of vitamin B12. Depending on the vitamin B12 concentration, testing for intrinsic factor blocking antibody, gastrin, and methylmalonic acid may be added.



Necessary Information


Ask patients if they have received a vitamin B12 injection within the last 2 weeks. Patient results will not reflect deficiency or malabsorption after recent B12 injection. If patient has received an injection within the past 2 weeks, this test should not be ordered.



Specimen Required


Patient Preparation: This test should not be performed on patients who have received a vitamin B12 injection or radiolabeled vitamin B12 injection within the previous 2 weeks.

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.6 mL

Collection Instructions:

1. Serum gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged, and the serum aliquoted into a plastic vial within 2 hours of collection.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 7 days
  Frozen  90 days

Reference Values

180-914 ng/L

Day(s) Performed

Monday through Saturday

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

82607

LOINC Code Information

Test ID Test Order Name Order LOINC Value
B12 Vitamin B12 Assay, S 2132-9

 

Result ID Test Result Name Result LOINC Value
B12 Vitamin B12 Assay, S 2132-9

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

Testing Algorithm

For more information see Vitamin B12 Deficiency Evaluation.

Report Available

1 to 3 days

NY State Approved

Yes

Forms

If not ordering electronically, complete, print, and send a Benign Hematology Test Request (T755) with the specimen