Intrinsic factor antibody test
Quick answer: This blood test looks for antibodies against intrinsic factor, a protein your body needs to absorb vitamin B12. Doctors usually order it when you have low vitamin B12 or a certain type of anaemia and pernicious anaemia is suspected.
- SampleBlood
- TakesAbout 5 minutes
- Before the testTell staff if you have recently had a vitamin B12 injection, as it can affect some test methods.
How the test is done
- 1Tell staff if you have had a B12 injection recently
- 2A nurse cleans a vein on your arm
- 3A needle draws blood into a tube
- 4The lab tests the sample for intrinsic factor antibodies
What your results can mean
Reading your report
Ranges and cut-offs differ between labs and methods, so discuss your result with your doctor.
If the result is outside the usual range
A positive result strongly supports pernicious anaemia, where the body cannot absorb vitamin B12 from food. A negative result does not rule it out, because many people with the condition test negative.
Who usually has this test
People with low vitamin B12 levels, a large-cell anaemia or nerve symptoms such as numbness and tingling.
Risks and aftercare
A small bruise is the only usual side effect; carry on with your normal diet.
Names and options
Also called: IFA, anti-intrinsic factor, IF antibody
Listed by the hospital as
- INTRINSIC FACTOR ANTIBODY, SERUM
Questions about this test
Why does a recent B12 injection matter?
High B12 levels in the blood can interfere with some test methods and give a false positive. Labs often advise waiting some days after an injection, so tell staff when you had your last dose.
Does pernicious anaemia need lifelong treatment?
Usually yes, because the body cannot absorb B12 from food. Your doctor will explain the treatment plan.
Can low B12 affect fertility?
Low B12 has been linked to fertility and early pregnancy problems in some studies. If you are trying to conceive, discuss your B12 result with your doctor.
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 →
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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.