Vitamin B12 test
Quick answer: A vitamin B12 test measures vitamin B12, which the body needs to make red blood cells and keep nerves healthy. It is ordered for anaemia, tingling or numbness, tiredness, memory problems, vegetarian diets, and on long-term medicines such as metformin.
- SampleBlood
- TakesAbout 5 minutes
- Before the testNo special preparation is usually needed.
- In fertility careVitamin B12 matters for the baby's development, so doctors may check it in people who are trying to conceive or pregnant, especially vegetarians.
How the test is done
- 1You sit down and the skin on your arm is cleaned
- 2Blood is drawn into a tube
- 3The test is often done with a blood count and folate
- 4A plaster is applied after the needle is removed
What your results can mean
Reading your report
Normal ranges differ between labs, so compare your result with the range printed on your report and discuss it with your doctor.
If the result is outside the usual range
A low level can be seen with a vegetarian diet low in dairy, poor absorption from conditions like pernicious anaemia, stomach or gut problems, or long-term metformin or acid-reducing medicines. A high level is usually seen with supplements or injections and is rarely a concern on its own.
Who usually has this test
Vegetarians, people with anaemia, tingling, numbness or memory problems, those on long-term metformin, and people trying to conceive or pregnant.
Risks and aftercare
You can continue any B12 tablets or injections as prescribed after the sample.
Names and options
Also called: B12, cobalamin, serum B12
Listed by the hospital as
- VITAMIN B12, SERUM
Questions about this test
Why is vitamin B12 deficiency common in India?
B12 comes mainly from animal foods such as milk, eggs, meat and fish, so people on a vegetarian diet with little dairy are at higher risk. Some medicines and stomach or gut problems can also reduce absorption.
Can low vitamin B12 affect fertility?
Low B12 has been linked with problems with ovulation and sperm in some studies, and it matters for the baby's development. If your level is low, your doctor will advise on supplements or injections.
Should I stop B12 supplements before the test?
Recent supplements or injections can raise your level. Tell staff what you take, and ask your doctor whether timing matters for your test.
Related tests
Tamara Hospital & IVF Centre, Rajajinagar
34/3, 10th Cross Road, opp. Vardhaka Sardar Patel School, 1st N Block, 2nd Stage, Rajajinagar, Bengaluru 560010
The hospital is open 24 hours. Call before you come to check the timing for your scan or sample collection.
Get directions ↗IVF Pulse fertility care at Tamara Hospital →
Reception
Waiting area
IVF lab
This page explains each test in general terms so you know what to expect. It is not medical advice: your doctor decides which tests you need and what your results mean. Reference ranges differ between laboratories. Updated 4 November 2026.