💊 Vitamins

Vitamin B12: What It Means for Your Health

Vitamin B12 (cobalamin) is a water-soluble vitamin found almost exclusively in animal products. It is essential for DNA synthesis, red blood cell formation, myelin production (the protective coating around nerves), and brain function. B12 deficiency can cause a type of anemia called megaloblastic anemia and irreversible nerve damage if left untreated. The body stores 2-5 years' worth of B12 in the liver, so deficiency develops slowly.

Full Name
Cobalamin (Vitamin B12)
Normal Range
200–900 pg/mL
Also Known As
Cobalamin, B12, Vit B12

Reference Range

LowNormal: 200–900 pg/mLHigh

Reference ranges may vary between laboratories, age groups, and sexes. The values shown are general adult reference ranges. Always compare your results to the specific range provided by your testing laboratory.

What Is Vitamin B12?

Vitamin B12 (cobalamin) is a water-soluble vitamin found almost exclusively in animal products. It is essential for DNA synthesis, red blood cell formation, myelin production (the protective coating around nerves), and brain function. B12 deficiency can cause a type of anemia called megaloblastic anemia and irreversible nerve damage if left untreated. The body stores 2-5 years' worth of B12 in the liver, so deficiency develops slowly.

Commonly included in:

Vitamin B12 TestAnemia PanelWellness Panel

What Does High Vitamin B12 Mean?

Above 900 pg/mL

Very high B12 levels can occur with excessive supplementation, liver disease (the liver releases stored B12 when damaged), chronic myelogenous leukemia, or polycythemia vera. While high B12 from supplements is generally not harmful, unexplained elevated B12 may warrant investigation for liver disease or blood cancers.

What Does Low Vitamin B12 Mean?

Below 200 pg/mL

Low B12 causes megaloblastic anemia (large, immature red blood cells), neurological symptoms (numbness, tingling, balance problems, memory issues), fatigue, and depression. Common causes include vegan/vegetarian diets without supplementation, pernicious anemia (autoimmune destruction of intrinsic factor), malabsorption from celiac disease or Crohn's, and long-term use of metformin or proton pump inhibitors.

Related Biomarkers in Vitamins

Vitamin D
Fat-soluble vitamin essential for bone health, immune function, and mood.
Range: 30–100 ng/mL
Folate
B vitamin critical for cell division, DNA synthesis, and fetal development.
Range: 3–20 ng/mL
Vitamin A
Fat-soluble vitamin essential for vision, immune function, and skin health.
Range: 30–65 ug/dL

Track Your Vitamin B12 Over Time

Upload your blood test results to Hemoly and see how your Vitamin B12 levels change over time. Get trend analysis, educational insights, and a personal health timeline.

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Medical Disclaimer

This information is for educational purposes only and is not intended as medical advice, diagnosis, or treatment. Reference ranges may vary between laboratories. Always consult a qualified healthcare professional for interpretation of your blood test results and before making any health decisions.