Vitamin B12: what your level actually means
Also known as: B12, Cobalamin, Cyanocobalamin · Updated 19 Aug 2026 · Educational — not medical advice
The short answer: Vitamin B12 below 200 pg/mL is deficient and 200–300 is borderline. Deficiency is especially common on vegetarian and vegan diets, and it matters: B12 protects nerves and makes red blood cells.
Where does your value sit?
This Vitamin B12 value is inside the normal range. Your lab's printed reference range takes precedence — ranges vary slightly between laboratories.
Convert Vitamin B12: pg/mL ↔ pmol/L
Labs report Vitamin B12 in either unit — same value, different scale. Type in either box.
What Vitamin tells you
B12 comes almost entirely from animal foods, so intake can quietly fall short for years — the body stores enough to hide it for a long time. Tingling hands or feet, fatigue, and memory fog are late signs. (Illustration is schematic.)
Common reasons it rises
- B12 tablets or injections — tell your doctor what you take, as it changes how the result is read
- Liver disease, or some blood and bone marrow disorders — a high level without supplements needs a cause looked for
And reasons it runs low
- Vegetarian or vegan diet without fortified foods or supplements
- Absorption problems — long-term antacids, metformin, gut conditions
- Age — absorption declines over time
Could a medicine be moving this number?
These medicines are known to shift Vitamin B12. Seeing one you take does not mean it is the cause, and it is never a reason to stop on your own — it is a reason to ask whether your result needs reading in that light.
- Metformin · Biguanide (blood sugar-lowering medicine for type 2 diabetes)Long-term metformin use can reduce how well the gut absorbs vitamin B12, so levels are sometimes checked periodically, especially if tingling or fatigue develops.
- Omeprazole · Proton pump inhibitor (acid-reducing medicine)Long-term use can lower stomach acid enough to reduce how well vitamin B12 is absorbed from food, so levels are sometimes checked after months to years of regular use.
- Pantoprazole · Proton pump inhibitor, PPI (acid-reducing medicine)Long-term acid suppression can reduce how well vitamin B12 is released from food, so doctors sometimes check B12 after months to years of regular use.
- Rabeprazole · Proton pump inhibitor (PPI)Long-term use can reduce absorption of vitamin B12 from food, since stomach acid helps release this vitamin for absorption; levels are sometimes checked after extended use, particularly over a year or more.
Never stop or change a prescribed medicine because of a lab result. Take the result and your medicine list to whoever prescribed it.
What should I eat?
Eat freely
- Eggs, if you eat them — One of the few vegetarian-friendly sources of B12
- Curd, milk and paneer — Dairy provides a steady, reliable source of B12
- Fortified cereals or fortified plant milk — Added B12 helps close the gap on vegetarian diets
- Fish or chicken, if you eat them — Among the richest natural sources of vitamin B12
- Fortified nutritional yeast, where available — An easy vegetarian add-on that boosts intake
Go easy on
- Alcohol in excess — Heavy drinking lowers B12 absorption and body stores
- Long-term unsupervised antacid use — Reduces stomach acid needed to absorb B12
Best avoided
- Relying only on plant foods for B12 — Plant foods alone rarely provide enough vitamin B12
- Skipping retesting after starting treatment — Levels need checking to confirm the deficiency is improving
One realistic day
- MorningA glass of milk or fortified plant milk
- BreakfastEggs or fortified cereal with milk
- Lunch2 rotis, paneer or egg curry, sabzi and curd
- EveningA cup of tea with a handful of roasted chana
- Dinner1 roti, fish or chicken curry, or dal with curd
Can I exercise?
Stop and get help if
- Chest pain, pressure or severe breathlessness — call emergency services now
- Numbness, tingling or weakness in hands or feet
- Fainting — call emergency services now; dizziness that does not settle with rest — see a doctor today
Exercise doesn't correct a B12 deficiency, but staying active supports energy and mood while levels recover.
Your week
- 5 days: a 20 to 30-minute walk at an easy pace
- 2 days: gentle stretching or yoga
- Rest when you feel unusually fatigued
Start here: Start with a short 10-minute walk on easy days
Skip for now
- Intense exercise until fatigue and tingling improve
Check with your doctor first: Anyone with numbness, tingling, memory changes, or a known gut condition affecting absorption should see a doctor rather than rely on diet alone.
General guidance for adults — not a personal diet plan. Your doctor or dietitian knows your full picture.
Checked against: B Vitamins — MedlinePlus · Vitamin B12 Fact Sheet for Consumers — NIH ODS · Vitamin deficiency anemia — Mayo Clinic
What to do next
Ask your doctor: “Tablets or injections — which fits my level?”
Ask your doctor: “Should we also check homocysteine or folate?”
Often confused with
Read together with
Questions people ask
I'm vegetarian — do I need a B12 supplement forever?
Plant-based diets provide very little B12, so a maintenance supplement or fortified foods are the standard long-term answer. It's inexpensive insurance for your nerves.
Share this guide
One value tells half the story.
Upload your full report — every value checked and explained. Free — no account needed.