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Intrinsic Factor Antibodies
99.00
The Intrinsic Factor Antibodies test detects autoimmune antibodies that impair vitamin B12 absorption. It is a key test for diagnosing pernicious anaemia.
Turnaround time
2 days
Biomarkers count
1
Same-Day Appointments
UKAS Accredited Labs
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Under 18? Patients under 18 can only be seen at GB Medlabs and Clinilabs, Monday to Friday only.
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Details about Intrinsic Factor Antibodies
What is the Intrinsic Factor Antibodies test?
The Intrinsic Factor Antibodies test is a blood test that detects antibodies directed against intrinsic factor, a protein produced by the stomach that is essential for the absorption of vitamin B12 in the small intestine.
When intrinsic factor is blocked by antibodies, vitamin B12 cannot be absorbed effectively, even if dietary intake is adequate. This leads to pernicious anaemia, an autoimmune condition that causes vitamin B12 deficiency and associated neurological and haematological complications.
This test is considered highly specific for pernicious anaemia and is used as part of a comprehensive B12 deficiency work-up.
Why do I need an Intrinsic Factor Antibodies test?
Vitamin B12 deficiency can cause irreversible nerve damage if not diagnosed and treated early. Identifying an autoimmune cause is essential for correct long-term management.
You may need this test if you:
- Have low or borderline vitamin B12 levels
- Have unexplained anaemia
- Experience neurological symptoms
- Do not respond to oral B12 supplementation
- Have suspected pernicious anaemia
- Have autoimmune conditions
- Have chronic fatigue or cognitive changes
Symptoms associated with vitamin B12 deficiency include:
- Fatigue and weakness
- Numbness or tingling in hands and feet
- Memory or concentration problems
- Balance difficulties
- Shortness of breath
- Pale or yellowish skin
- Sore or smooth tongue
Benefits of the Intrinsic Factor Antibodies test
- Confirms autoimmune B12 deficiency
Identifies pernicious anaemia specifically. - Highly specific diagnostic marker
Few false positives. - Guides correct treatment strategy
Indicates need for lifelong B12 injections. - Prevents neurological complications
Enables early intervention. - Clarifies cause of unexplained anaemia
Differentiates dietary from autoimmune causes. - Supports long-term disease management
Essential for monitoring and follow-up. - Complements B12 and folate testing
Adds diagnostic clarity. - Simple blood test
Requires only one sample.
Step by step – how the test works
You can access Intrinsic Factor Antibodies testing UK-wide through two options:
- Clinic appointment
Attend your nearest UK clinic where a healthcare professional will take your blood sample. - At-home or hotel visit (£60 extra)
A qualified phlebotomist comes to your home or hotel, so you don’t need to travel.
Your sample is analysed in an accredited UK laboratory, and results are delivered securely.
Your results explained
Negative intrinsic factor antibodies
Pernicious anaemia is less likely, though not completely excluded.
Typical UK interpretation:
- Intrinsic factor antibodies: Negative
Positive intrinsic factor antibodies
Strongly indicative of pernicious anaemia.
Typical UK interpretation:
- Intrinsic factor antibodies: Positive
Clinical interpretation
A positive result is highly specific and usually confirms autoimmune B12 malabsorption.
Results should be interpreted alongside B12, folate, full blood count and clinical findings.
How It Works
Simple steps to get your results
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Book Online
Choose your test online and book in seconds. Select your preferred clinic location or home visit option.
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Visit or Test at Home
Attend one of our UK or London clinics, arrange a home nurse visit, or use a finger-prick kit where available.
3
Get Your Results
Your sample is analysed by accredited UK laboratories, with secure results delivered directly to you.
Take control of your health with London Blood Tests
WhatsApp UsHow to Prepare for Your Test
Follow these guidelines for accurate results
Sample Timing
Where possible, attend your blood test between 7am and 12pm. Please wait until any short-term illness or infection has fully resolved before testing. Avoid intense exercise for 24–48 hours beforehand, as this can affect certain markers.
Fasting & Hydration
Fasting is not always required, but some tests may recommend it. If fasting is advised, avoid food for 8–12 hours before your appointment and drink water only. Stay well hydrated, as this helps with sample collection and accuracy.
Medications & Supplements
Continue prescribed medications unless advised otherwise by your clinician. Avoid vitamin, mineral, or biotin supplements for at least 24–48 hours before your test, as these can interfere with results. If you are unsure about any medication or supplement, please let us know before your appointment.
Hormones & Menstrual Cycle
For hormone-related tests, timing within your menstrual cycle may be important. If relevant, follow any specific guidance provided on your test page.
If you have any questions or special circumstances, our team is happy to advise before your appointment.
Frequently Asked Questions
Yes. It is highly specific for the condition.
Yes. Some cases require additional testing such as parietal cell antibodies.
No fasting is required.
Yes. It is part of a full B12 deficiency assessment.
Yes, with lifelong vitamin B12 replacement.
Usually not reliably; injections are preferred.
It has an autoimmune association and may cluster in families.
Yes. Anaemia may be mild or absent initially.
Yes. Home or hotel phlebotomy is available UK-wide for £60 extra.
Yes. Long-term management planning is required.
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