B12
A vitamin essential to nerves, blood cells, and energy.
What is it
Vitamin B12 is required for red blood cell formation, neurologic function, and DNA synthesis. Deficiency is common, particularly with age and in vegetarian/vegan diets.
Why it's measured
B12 deficiency has been associated with anemia, fatigue, and neurologic symptoms in published research.
Reference range
Standard laboratory reference
200 – 900 pg/mL
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
What results may indicate
Elevated
Generally not clinically concerning. May reflect supplementation.
Lower
Has been associated with anemia and neurologic symptoms in research literature. MMA can help confirm deficiency.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Measured in routine evaluations of fatigue, anemia, or neurologic symptoms.
Related markers
Common questions
Vitamin B12 is required for red blood cell formation, neurologic function, and DNA synthesis. Deficiency is common, particularly with age and in vegetarian/vegan diets.
It's one of the markers used to build a fuller picture of your health. On its own it tells you very little, so it's most informative when reviewed alongside related markers.
It's measured from a standard blood draw at Quest or LabCorp. Vitamin B12 is one of the markers included in the OPTML Apex Panel, where your results are read across systems and reviewed by a U.S.-licensed physician.
Reference ranges vary by laboratory, and a single value rarely tells the whole story. Review your result with a physician in the context of your other markers, symptoms, and history.
Vitamin B12 is one signal among many. Answer a few quick questions and we’ll point you to the panel that fits.
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Explore the Apex Panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.