Vitamin B12
Also known as: B12 test, Vitamin B12 level, B12 ka test, vitamin B12 ki kami ka test
The level of vitamin B12, which the body needs to make red blood cells and keep nerves healthy.
Why it's ordered
Investigating anaemia with large red cells, tingling or numbness, memory problems, and in people on long-term metformin or acid-reducing medicines.
Preparation
No fasting needed, though some labs prefer it. Stop B12 supplements a few days before if your doctor agrees.
Typical adult values
| Low | below 200 pg/mL (148 pmol/L) |
|---|---|
| Borderline | 200–300 pg/mL |
| Usual adult range | roughly 200–900 pg/mL |
Ranges vary between labs and methods. Always use the range printed on your report.
If it's high
High B12 is usually from supplements or injections. Persistently high levels without supplements should be discussed with a doctor.
If it's low
Low B12 can cause anaemia and nerve damage. Causes include a vegetarian diet, metformin, acid-reducing medicines and absorption problems.
Good to know
A borderline result does not rule out deficiency. Doctors may add a methylmalonic acid (MMA) test to confirm.
Common questions
Is a B12 of 250 low?
It is borderline: 250 pg/mL falls in the borderline range of 200–300 pg/mL. A borderline result does not rule out deficiency. Always use the range printed on your report.
Do I need to fast for a B12 test?
No fasting needed, though some labs prefer it.
What can cause low B12?
Causes include a vegetarian diet, metformin, acid-reducing medicines and absorption problems. Low B12 can cause anaemia and nerve damage.
Why is my B12 high?
High B12 is usually from supplements or injections. Persistently high levels without supplements should be discussed with a doctor.