Vitamin B12 (REFL)
The Vitamin B12 (REFL) test measures the amount of vitamin B12 in a serum sample. Clinicians use it when evaluating conditions associated with decreased B12 levels, read alongside a person's history and other findings.
About this test
This test reports the concentration of vitamin B12 in a 1 mL serum sample, measured by immunoassay. Quest describes decreased levels as associated with conditions including pernicious anemia, prior total or partial gastrectomy, malabsorption, and certain congenital biochemical disorders.
It is set up as a reflex test: depending on the initial result, the laboratory may automatically perform additional testing on the same sample, without requiring a separate order from the ordering clinician.
Who might consider this test?
- Because B12 status can relate to several different conditions, the reason for testing shapes how a clinician reads the result.
Test details
| Quest code | 30663 |
|---|---|
| Methodology | Immunoassay |
| Sample type | 1 mL serum |
| Collection | Quest patient service center |
Related tests and panels
Measures vitamin B12 (cobalamin), a nutrient marker used to evaluate decreased le…
Quest resources
Additional details
What this test looks at
The test reports one value: the level of vitamin B12 in serum. If that initial result meets criteria the laboratory applies, additional testing is added automatically as part of the reflex, rather than through a new order.
This test isn't orderable through the store yet. Requesting it tells us you want it and puts you on the list to be told when that changes — there is no charge and no commitment, and requesting does not place an order.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does the Vitamin B12 (REFL) test measure?
It measures the concentration of vitamin B12 in a serum sample, using immunoassay methodology.
How is the sample collected?
The test uses a 1 mL serum sample from a routine blood draw.
Do I need to prepare for this test?
No preparation instructions are listed for this test, though people follow any instructions their ordering clinician provides.
What does "REFL" mean in the test name?
REFL indicates this is a reflex test. Depending on the initial vitamin B12 result, the laboratory may automatically run additional testing on the same sample.
Why might a clinician have someone tested for vitamin B12?
Quest describes decreased vitamin B12 as associated with conditions such as pernicious anemia, prior total or partial gastrectomy, malabsorption, and certain congenital biochemical disorders.