Alternative names, keywords

Vitamin B12, cobalamin

Samples required

Clotted blood (gold cap, 5 mL tube). Smaller tubes are available for paediatric samples.

Vitamin B12 determinations should be performed on samples from fasting patients.

Test indications


(click here for folate)

Factors affecting test performance/ results

Samples with extremely high total protein concentrations (hyperproteinemia) are not suitable for use in this assay.

The presence of immunoglobulin-vitamin B12 complexes may cause unexpectedly high values of vitamin B12.

The assay is designed to avoid interference due to anti-intrinsic factor antibodies.

Biotin may interfere - samples should not be taken from patients receiving therapy with high biotin doses (i.e. > 5 mg/day) until at least 8 hours following the last biotin administration.

In rare cases, interference due to extremely high titres of antibodies to analyte-specific antibodies, streptavidin or ruthenium can occur.

Results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Reference range

197 - 771 ng/L

Source: Roche Cobas® Vitamin B12 II kit insert, 2015-07, V 2.0

Turnaround time

24 hours (weekdays)


Biochemistry (Automation)