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Doctor's Assessment Included

Every result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.

Vitamins

Intrinsic Factor Antibodies

Intrinsic Factor Antibodies tests for an autoimmune cause of B12 deficiency known as pernicious anaemia. This test may help explain why B12 levels remain low despite supplementation and guide your healthcare provider towards appropriate treatment.

What It Measures

This test detects antibodies directed against intrinsic factor, a protein produced by stomach cells that is essential for vitamin B12 absorption in the small intestine. A positive result may suggest an autoimmune mechanism is interfering with B12 uptake.

Why It Matters

Understanding whether an autoimmune mechanism is causing your B12 deficiency is important for selecting the right treatment. Pernicious anaemia requires a different approach than simple dietary deficiency, and early identification could prevent worsening symptoms.

When to Test

Testing may be recommended when you have persistently low B12 levels despite supplementation, if pernicious anaemia is suspected, or if you have other autoimmune conditions. Your healthcare provider can determine whether this test is appropriate for your situation.

Symptoms

Low Levels

This test measures antibody presence rather than a continuous range. A negative result suggests intrinsic factor antibodies were not detected, which may help rule out pernicious anaemia as a cause of B12 deficiency.

High Levels

A positive result for intrinsic factor antibodies may be associated with symptoms of pernicious anaemia including severe fatigue, weakness, tingling in extremities, cognitive difficulties, and glossitis. Your healthcare provider should guide further evaluation and treatment.

Lifestyle Tips

If intrinsic factor antibodies are detected, your healthcare provider may recommend B12 injections rather than oral supplements, as absorption through the gut may be impaired. Regular monitoring and follow-up with your provider is important for managing this condition.

Frequently Asked Questions

What is pernicious anaemia?
Pernicious anaemia is an autoimmune condition where the body produces antibodies against intrinsic factor, a protein needed to absorb vitamin B12 in the gut. Without adequate intrinsic factor, B12 absorption may be severely impaired regardless of dietary intake.
Can intrinsic factor antibodies come and go?
Once intrinsic factor antibodies are detected, they generally persist. However, test sensitivity is not 100%, so a negative result does not completely rule out pernicious anaemia. Your healthcare provider may recommend additional testing if clinical suspicion remains.
How is pernicious anaemia treated if this test is positive?
Treatment typically involves regular vitamin B12 injections, as oral absorption may be impaired. Your healthcare provider will determine the appropriate frequency and dosage based on your individual needs and response to treatment.