Been advised to get tested for intrin... - Pernicious Anaemi...

Pernicious Anaemia Society
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Been advised to get tested for intrinsic factor antibodies


Hi, I’m new to this site, I was diagnosed with Hashimotos Oct last year and have been trying to get my dose correct however I still have symptoms:-

Spacey balance feeling

A weird temperature feeling mainly down my arms (it’s not hot or cold) but sort of tingly but it sometimes makes me feel drained

Ringing in my ears

Tired and lack of motivation

Not tolerating alcohol

Low ferritin and my red blood cells on the low side

I have been taking B12 supplements so have been told I can’t rely on their readings.

I have also been advised to do a loading dose of B12 injections...

Do I wait until blood results before doing injections?....will the Dr always agree to trialling B12 injections or can you do yourself?

Could I take sublingual B12 and if so which is the best sort?

This is all very new to me so any advice you need to fast for the blood test.., have it any particular time of day etc...

Any advice would be appreciated.

Thank you 🙏 😊

12 Replies
clivealiveForum Support

Hi jamjar67 having Hashimoto's may put you at an elevated risk of developing a Vitamin B12 deficiency and some of the symptoms you list can be attributed to that.

I would certainly advise that you speak with your doctor before taking any supplements and/or tests as that would "skew" the results.

In the first instance I would ask your doctor to test your Vitamin B12, Folate and Iron levels plus perhaps Vitamin D.

You would not normally fast for the above tests but your doctor would advise you.

The Intrinsic Factor Antibody (IFA) test is to check whether you have Pernicious Anaemia (P.A.) but sadly the IFA test is unreliable in that it gives false negatives in people with PA half the time. So a negative result doesn't mean that you don't have PA. However, a positive result is a sure-fire, 95% certain indicator of PA.

I am not a medically trained person but I've had Pernicious Anaemia (one of many causes of B12 deficiency) for more than 46 years.

I wish you well.

Weenibzie in reply to clivealive

Clive what clinic diagnoses hashimotos if u don't mind me asking

clivealiveForum Support in reply to Weenibzie

I'm sorry Weenibzie I don't know the answer as I'm not a medically trained person.

Perhaps jamjar67 can help you as she does have a diagnosis of Hashimoto's.

jamjar67 in reply to Weenibzie

Hi Weenibzie to confirm Hashimoto's you have to have thyroid antibodies in your blood which can be done with a blood test.

Ideally you should ask for the following to be included in the test


Free T4

Free T3

TPO antibodies

Tgab antibodies




Vit D

Many doctors refuse to prescribe for antibodies if TSH is 'anywhere in range' but it is advised by Dr Toft, who was President of tje BTA, that if antibodies are present to start on a 100mcg of levo to 'nip things in the bud'.

You should go on the Thyroid Uk Website, loads of really good and up to date information.

jamjar67 in reply to clivealive

Hi Clive, thank you for your response, I have put my most recent results below.... but I have been having B12 in my B vits supplement (which I dont take for a week before blood draw but I understand that makes no difference as you have to eliminate it for about 5/6 months to get a true baseline)

Ferritin 14.1 ug/L (13 - 150)

Folate - Serum 14.48 ug/L (>3.89)

Vit B12 Active 123 pmol/L (37.5 - 188)

Vit D 97.1 nmol/L (50 - 175)

I have been advised to trial B12 injections monthly or bi monthly following a loading dose, this is because my red blood cells are on the low side...

Haemoglobin 129 g/L (120 - 160)

Haematocrit 0.376 L/L (0.35 - 0.47)

Red Cell Count 4.07 x 10^12/L (3.8 - 5.8)

MCV 92 fl (81 -98)

MCH 31.8 pg (27 -33)

MCHC 344 g/L (300 - 350)

RDW 14.0% (11.5 - 14.4)

I know nothing about all this but I just wanted to ask...

If my intrinsic antibody test comes back negative is it harmful to trial the B12 anyway?

Also I'm worried if the test comes back negative that the Drs may refuse to trial me then I'll have to do it myself - if this is the case I have no idea how to go about getting B12 to inject luckily my daughter is studying medicine and would be able to help me with the injection but I have no idea where I would get the B12 and the needles from should it come to this?

Thanks again for your help!

fbirder in reply to jamjar67

Your active B12 is nice and high. That means that the oral supplements you have been taking are doing a good job of getting B12 into your body.

Your Mean Cell Volume is towards the lower end of the range, as is your ferritin. That strongly suggests that your lowish blood cell count is much more likely to be caused by iron deficiency rather than a B12 deficiency.

I really don’t think that B12 injections could possibly do more than the oral supplements and that you should concentrate on fixing any possible iron deficiency.

jamjar67 in reply to fbirder

Thank you so much.... I have started taking iron supplements and will be testing again beginning of Apr to see how my body is responding to them, I know it takes 3 months to properly show but hopefully this test will indicate that my levels are slowly moving in the right direction 🤞

Jumping on here : but any b12 oral supplements will screw up most blood test including masking a deficiency that can only be rectified by injection. Homocysteine test is good when supplementing

jamjar67 in reply to boru

Thank you... I'm going to the Drs today so shall ask for both tests....

fbirder in reply to boru

If taking oral supplements raises the Active B12 in the blood then that is the important thing. It shows that the deficiency is such that it doesn't need to be controlled with injections.

A hCys test will still be affected by taking B12 supplements.

jamjar67 in reply to fbirder

I think maybe because my level has dropped slightly from my test in Dec which was

Vit B12 Active 129 pmol/L (37.5 - 188)

and because of my continuing symptoms is why I’ve been advised to check for intrinsic factor antibodies...., although I have never tried sublingual B12 only B complex capsules, so maybe I should try the drops first and test again.... how long does it generally take to see a difference ?

fbirder in reply to jamjar67

Although the Active B12 test is more accurate than the serum test, the two results of 129 and 123 are, essentially, the same. Both are high.

You might expect the presence of IF antibodies if you weren’t absorbing oral B12. But you obviously are, so the antibody test wouldn’t be useful.

Sublingual will almost certainly not get any more B12 into your blood than you have from the tablets.

What might be useful are tests for methylmalonic acid and homocysteine. These are two of the chemicals used up in reactions mediated by B12. If you have a functional deficiency (lots of B12 in the blood, but it’s not getting to the right places in the cell) then one, or both, of those will be raised.

Ask for MMA and hCys tests, or look into getting them done privately.

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