vitamins · B12
Vitamin B12
A vitamin essential for nerve function, DNA, and red blood cell formation. Deficiency can cause anemia and nerve symptoms and is more common with age, plant-based diets, and certain medications.
This page is general wellness education, not medical advice. Your own lab’s reference range and your clinician’s interpretation always take precedence.
Typical reference range
| Group | General range |
|---|---|
| Adults | ~200–900 pg/mL; values 200–300 may be borderline |
Optimal-band note: Some practitioners prefer B12 above ~400 pg/mL, since low-normal values can still coincide with deficiency on confirmatory tests (e.g. methylmalonic acid). Soft target only.
Units: pg/mL. Ranges vary by lab and assay — read yours against the range printed on your own report.
What high Vitamin B12 can mean
- Supplements / injections
- Liver disease
- Some blood conditions
What low Vitamin B12 can mean
- Low intake (vegan/vegetarian)
- Poor absorption (pernicious anemia, gut conditions)
- Metformin or acid-reducing drugs
- Older age