Pernicious Anaemia Society
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Daily b12 dosage?


I had intrinsic factor antibodies test that was negative, but a lot of b12 deficiency symptoms - Gp treated me with loading doses for 2 weeks.

I was wondering what dose I should take on a daily basis?

I think My problem is low stomach acid due to hypothyroidism so not pernicious anaemia.

I’ve bought the better you spray - but it says 1200mcg daily?! Which is 1500% of never- sounds like a lot. Surely a normal replacement dose would be enough?

It also has chromium - does that affect thyroid?

What’s the normal dosage for general b12 deficiency? Any advice appreciated.

Many thanks

12 Replies

Hi Saya85 If you still had neurological symptoms after the loading dose they should have continued "until there is no further improvement" according to the N.I.C.E guidelines below. Click on the link, then on "Scenario: Management" and scroll down to "Treatment for B12 deficiency"

I believe there is some cross over of symptoms with


Do you know what your Folate level is?

It is also important that your Folate level is monitored as this is essential to process the B12.

There is a complex interaction between folic acid, vitamin B12 and iron. A deficiency of one may be "masked" by excess of another so the three must always be in balance.

Symptoms of a folate deficiency can include:

symptoms related to anaemia

reduced sense of taste


numbness and tingling in the feet and hands

muscle weakness


Folic acid works closely with vitamin B12 in making red blood cells and helps iron function properly in the body.

I am not a medically trained person but I've had P.A. (a form of B12 deficiency) for more than 45 years.

I wish you well


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Hi Clive.

Thanks- yes I am supplementing with iron and folic acid also as I tend towards microcytic Anaemia- but I think I should have started it earlier.

My symptoms improved almost immediately after b12 injections and since they’ve stopped it’s started to creep in just a little bit. They will probably give me a boost in 3 months.

But assuming I don’t have pA I believe the oral spray will work quite well- and I will check again in a couple months to see.

I was just wondering what a normal dose would be?

Is 1200mcg too strong?


Personally I have used the recommended dosage of the BetterYouB12 spray every day for some 18 months and I think it has helped "bridge the gap" between injections but not completely eradicated some neurological symptoms in the run up to the next one. My wife is convinced that the spray helped me get through a quite strenuous holiday last year.

At four squirts a day the spray will last about six weeks so give it a try.

Fortunately you cannot "overdose" on B12 so it will do you no harm.

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Brilliant- that’s why I was worried about overdosing on b12.

I wonder why doctors are so scared of injections and having too high b12 levels then?


Thanks for your comment below regarding likelihood of PA. I think given my recent issues I don’t have the energy to go back to the Gp again. If I can get 3 monthly injections and can use the spray in between then hopefullly that should manage the pA if I do have it?

If it doesn’t work then I’ll go back to GP. He clearly has limited understanding and experience with PA and b12 as evidenced thus far but he is relatively open to treating symptoms.

It’s a fine line between being labelled an informed patient and a hypochondriac so I think I’ll save my energy for the bigger battle!

Thanks again


A gastroenterologist told me that P.A. patients have no or low Stomach acid (achlorhydria /Hypochlorhydria ) due to antibody attack on the pareital cells which produce the Intrinsic Factor and Hdrochloric acid , both necessary for the breakdown and absorption of Vitamin B12 ( it’s the most difficult of vitamins to absorb).

Intrinsic Factor test is most unreliable. You can have PA and the test can come up negative . Your symptoms need treating , not the test result . I have PA , but the only treatment that works for me is injections . I have to self inject as the NHS won’t let me have more than one injection every 3 months , and my symptoms start returning long before that .




I was told that IFA test was more specific than gastric parietal cell testing -(which GP neglected to do) but either way you can have false negatives in both.

I tend towards microcytic anaemia rather than macrocytic which would again probably be a strike against Pa.

low stomach acid is common in hypothyroid sufferers which is why we’re often b12 deficient too.

I haven’t ruled out PA diagnosis as even the lab says IFa test isn’t a full diagnosis. But for now I wanted to try the spray as new research is showing it works as well as injections for some people.

I will have my booster in 3 months and hopefully use sprays in between.

What dose do you take daily ?


the test is indeed more specific than GPC but it is a lot less sensitive and tends to produce false negatives 40-50% of the time depending on the exact test method so a negative is a long way from showing that you don't have PA.

Personally I'm not sure that hypothyroidism will result in lower stomach acidity - it can result in slower transit of food through the gut which can result in conditions that affect B12 absorption such as SIBO. I think it is more likely, as there is a high cross over between autoimmune hypothyroidism and PA, which definitely does lead to low stomach acidity - so think it is more likely that you have developed a second auto-immune condition.

If you have an absorption problem then rule of thumb would be that you are going to absorb 1% of anything that you are taking so you would only be absorbing 100th of the amount in the spray.

However, just a rule of thumb - all you can really do is try and see how it goes - if symptoms come back try more frequent. However,these supplements also don't work for everyone.

this may be relevant in relation to the timing of the supplement with levo


Thanks !

Yes I do realise it could be a false negative but don’t have the energy to fight the GP- as long as I’m getting injections and can use the spray I’m hoping it will work. If it doesn’t il have to go back.

thansk for the extra info- Will look into it more - I def think it’s stomach acid related, regardless of the cause.

Wondering whether to push for finding the cause or just treat the acid issue anyway.

It’s an uphill battle

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I need to inject 1mg ampoule once a week to keep well . Nothing else works for me infortunately .


I think reasons that docs brush us off on injections or seem to not care is because they don’t make a lot of $ off the injections, or caring for b12 deficiency patients. Most aren’t even educated enough about it. Sad, but true! I find that I don’t get much relief and symptoms return unless I keep my oral supplements at a high dose. I take 5-10,000 mcg. sublingual b12 daily, plus 5,000 mcg. of folate. Remember, it’s micrograms which only equal to about 5-10 “milligrams” of what I take. Also, we only absorb a portion of what we’re taking, so it ends up being lower % of our dosage that’s getting absorbed. That’s why a higher dose is very important. So actually, you’re on a very low dose if you’re b12 deficient. Hope this helps. <3

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Problem is u need huge blood levels of B12 as your body can only actually use small amounts. If it's oral i would wonder if it is helping at all. Did u feel better when on loading dose? Once u are being supplemented blood tests are irrelevant because u have no idea how much u can actually use. Won't your gp give u injections? Normal nhs injection guidelines are 1mg per 3 months. Still not enough but better than oral in my experience.

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Note on iron supplementation. Inside health - radio 4 says new research shows take supplements on alternate days as it is toxic absorbtion is much better if not done every day. Give gug time to recover.


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