Nutrients system

Vitamin B12

B12

A vitamin essential to nerves, blood cells, and energy.

What is it

Vitamin B12 — in plain English.

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

What B12 can reveal.

B12 deficiency has been associated with anemia, fatigue, and neurologic symptoms in published research.

Reference range

Where most laboratories draw the standard line.

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

Higher vs. lower B12 — at a high level.

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

When B12 is typically run.

Measured in routine evaluations of fatigue, anemia, or neurologic symptoms.

Related markers

Often measured alongside B12.

Measured in

B12 is one of 160 biomarkers in the Apex Panel.

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
160 biomarkers13 body systemsPhysician-reviewed
Back to all biomarkers

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.