Vitamin B12 (Cobalamin)
Vitamin B12 is essential for nerve function and red blood cell production. Deficiency is common in vegetarians, older adults, and people on acid-blocking medications.
Have your own lab results?
Upload your test and get a personalized meal plan targeting your specific vitamin b12 (cobalamin) level.
What Vitamin B12 (Cobalamin) measures
B12 is a water-soluble vitamin needed for DNA synthesis, the myelin sheath that insulates nerves, and red blood cell formation. Low B12 can cause anemia, fatigue, numbness, balance issues, and memory problems. If untreated, the nerve damage can become permanent.
Normal ranges
Reference ranges may vary slightly by lab. Always use the range provided on your specific test report.
What affects your vitamin b12 (cobalamin) level
- Vegetarian or vegan diet (B12 is naturally only in animal foods)
- Aging (reduced stomach acid lowers absorption)
- Proton pump inhibitors and metformin (impair absorption)
- Gastric bypass or GI surgery
- Pernicious anemia (autoimmune attack on intrinsic factor)
- Crohn's, celiac, or other malabsorption conditions
Foods that may help
Clams and oysters
Highest natural B12 content per serving
Liver and beef
Concentrated B12 plus heme iron
Sardines and salmon
B12 plus omega-3s
Eggs and dairy
Reliable everyday source
Fortified nutritional yeast
Practical option for vegans
When to see your doctor
Any level below 300 pg/mL combined with fatigue, numbness, brain fog, or balance issues warrants prompt treatment — nerve damage from B12 deficiency can become irreversible. Test alongside folate, since the two can mask each other.
Related biomarkers
Get your own personalized plan
Upload your health test PDF and our AI will create a personalized interpretation and meal plan targeting your specific biomarkers, in minutes.
Educational content only · Not medical advice