Vitamin B12
Label Mnemonic: B12
Epic Lab Code: LAB67
Downtime Form: A-1a General Laboratory Requisition
6240 RCP
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
3 mL whole blood in light green top tube or TWO Microtainer® devices.
Delivery Instructions:
Deliver to laboratory immediately after collection. Protect sample from light.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
Normal: 211 - 946 pg/mL
Indeterminate: 150 - 210 pg/mL
Deficient: is less than 150 pg/mL
Refer to BD Microtainer® Tubes product sheet for detailed sample collection instructions.

New analytical immunoassay with different reference range instituted on 11/26/2013.

This test is also performed in the Iowa River Landing (IRL) clinical laboratory (for specimens drawn at that site).
Test Limitations:
The assay is unaffected by icterus (bilirubin is less than 65 mg/dL), hemolysis (Hb is less than 1.0 g/dL), lipemia (triglycerides is less than 1500 mg/dL) and biotin is less than 50 ng/mL. (criterion: recovery within plus or minus 10% of initial value).

In patients receiving therapy with high biotin doses (i.e. is greater than 5 mg/day) no sample should be taken until at least 8 hours after the last biotin administration.

No interference was observed from rheumatoid factors up to a concentration of 1500 U/mL.

In vitro tests were performed on 54 commonly used pharmaceuticals. No interference with the assay was found.

In rare cases interference due to extremely high titers of antibodies to streptavidin and ruthenium can occur.

For diagnostic purposes, the vitamin B12 findings should always be assessed in conjunction with the patient's medical history, clinical examination and other findings.
Electrochemiluminescence Immunoassay
CPT Code:
See Additional Information:
Specimens Requiring Immediate Delivery