Pernicious Anaemia Society
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Um...dumb question maybe?


I have been receiving b12 shots for the past 8 weeks. Initially the walk in Dr said I will get 1 shot a week for 4 weeks then one monthly.

By my 5th week, I was in desperate need of one. I am able to last 10-12 days before I notice that dreadful drop. So we agreed that I come in whenever I feel the need to get a shot...weekly, every other week or every 3 weeks, etc.

Now my stupid question is...why am I getting these shots? I have vaguely researched why people get b12 shots, but I cannot really understand the garble.

Do I have pernicious anemia?

4 weeks ago while visiting my other home (across the country), I needed a shot, so I went in to my GP. He asked me if I have pernicious anemia. I didn't know what to tell him. I just told him that I get weekly b12 shots. We had my blood work faxed over and next thing you know, I'm given my shot and he is gone.

I feel stupid asking my walk in Dr...weeks later what the diagnosis is.

Can anyone tell me if it is pernicious anemia or are there other reasons for needing a b12 shot? And what can I do help make the time in-between my shots longer?


8 Replies

Do you know which bood tests you've had? Serum cobalamin? Intrinsic factor antibodies? Gastric parietal cell antibodies?

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Just had a quick look at your posts, and you have Lupus. It's more likely you have Pernicious Anaemia than other forms of B12 deficiency, but the tests results would help to determine that.



I do not know what type of blood tests I have had done. I've had about 6 bout of blood tests done this year, because I have lupus. I have a few of the results. I've tried to look over them and only one show a slight deficiency in b12. This being said, I've had blood work done in 2 different provinces and the results are displayed differently, so trying to understand them makes my skin.

I tried to kine them up and compare then cross-reference with information from the internet, that is when it all becomes a blur.


Hi Lara 4228. If you're being given B12 injections then at sometime you will have had a serum B12 blood result that shows you are deficient in vitamin B12. Perhaps this was during routine blood tests at your lupus clinic or during a routine test via your GP. So, you will have been diagnosed with a vitamin B12 deficiency and this is why you will have been given vitamin B12 injections.

There are a number of reason why you could have B12 deficiency: medications that prevent absorption of B12, gastric or intestinal surgery, anaesthetic, dietary deficiency (are you a vegan), pernicious anaemia - to name but a few.

As you have one autoimmune disease, it is quite likely that you may develop another (autoimmune dieseases tend to come along in groups), so this may predispose you to pernicious anaemia (another autoimmune disease) - as Hillwoman has pointed out.

You will not be thought stupid if you go back to either of the GP's you see to discuss this (perhaps your more regular one would be best). Often, it takes a while for the implication of any treatment to 'sink in' so it is quite usual to ask questions at some stage following a diagnosis. Especially if this has not been explained clearly to you.

If he has not done so, your doctor may want to investigate why you have the deficiency and / or whether or not you have pernicious anaemia. The standard tests for pernicious anaemia are anti-intrinsic factor (anti-IF) and pariatel cell antibodies (PCA). Though it must be said that these tests are only 50% accurate. This means that you can test negative but still have pernicious anaemia (this is called antibody negative pernicious anaemia - though not many GP's are are aware of this as a diagnosis).

One of the problems of having these tests for PA is that if you test negative, your GP may withdraw your B12 treatment (even though you have been diagnosed as deficient and still need that treatment). Odd, I know, but many GP's are remarkably I'll-informed about B12 deficiency and PA!

The treatment for PA is the same as the treatment for B12 deficiency: B12 injections. As fbirder pointed out in a reply elsewhere today, as you are already having the standard PA treatment (B12 injections), is it 'worth' having the IF test and risking the treatment being stopped if the result is negative? Only you can know the answer to that. Of course if the B12 injections were simply stopped in the future, then if would certainly be worth having the IF test, since a positive PA result means that you should automatically get B12 injections, for life 😀.

The really good news here is that, from what you say, your 'usual' GP seems quite happy to give you B12 injections whenever you feel you need them (this is very rare and much to be welcomed). Many people here keep symptoms diaries/logs to enable them to predict how often they need jabs (for instance, there are usually one or two symptoms that return before the others - mine is fatigue / fog). If you can do this, you will be able to tell how often you need the jabs and arrange an appropriate regime that will help stop your symptoms returning. A good way to avoid that 'dreadful drop'!

I don't use other supplements between jabs but some people here use nose drops, sublingual lozenges, or B12 patches (in order of efficacy) to top-up between jabs. (Some use the nasal drops instead of injections - but not many). B12 injections are the best method of deliver, especially if you have neurological symptoms. B12 tablets will not work if you have an absorption problem (the most common cause of B12 deficiency and always present in PA). If you decide to supplement via the non-injection route and are not sure what to get or where to get it from, do another post and people will be able to advise.

There are some PAS pinned posts to the right of this page when you log on. They provide some really good information about guidelines and treatment regimes, so are well worth a read.

Everybody here knows how difficult it is when first diagnosed - masses of information that just as well be in a foreign language, foggy heads, difficulties with GP's (yours sounds better than most 😀) etc. I've kept this post very general so that you're not overloaded with compliacted information...just hope it helps to sort out the basics with which to approach your GP. Good idea to make a list of questions before you go (I always forget something and kick myself afterwards 😀!).

B12 deficiency is quite complex, it affects all systems in the body and can be experienced quite differently by anybody who has it. So please do keep posting if you need any further help or advice. Lots of people here to help, when needed 😀.

Good luck with your GP and please let us know how you get on.

Take care X


Thank you very much for the leads and information.

The fatigue and fog I thought were due to lupus. They diminish within 30 minutes of getting the injection. I was so astonished by it. I wouldn't know any other symptoms as I have so many unconnected, odd things going on.

November 30 I see the lupus clinic in Montreal (finally!!!). I think I might be hoping for a miracle to answer some of these odd occurring symptoms.

I will check out those posts as suggested.

Thank you very much

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Hi Lara4228. Don't know,if you've seen it but there's a symptom check list on the PAS website and you could also check out - lots of good information there and also another checklist (with slightly more detail about symptoms).

It's so difficult, isn't it - so many other cross-over symptoms with other autoimmune conditions 😖.

Hope all goes well at the lupus clinic and that they are able to do something to banish at least some of your symptoms.

Take care x


Don't feel the question is dumb - I suspect that if it was given as an exam question to a lot of medics 90%+ would get the answer wrong!

Loading shots will be given as the most effective way of raising serum B12 levels quickly if someone is seriously deficient.

If you have a problem absorbing B12 (PA is one cause - Foggyme has listed a number of others) then you will need to find a way of getting B12 in to your body that doesn't rely on it being absorbed in the gut (though for some, flooding the gut with really high doses can work and enough does get through) - and injections are just the most efficient way of doing that and the easiest way to know that it really has got inside your body and will be getting into your blood stream.

Although the body is very efficient at storing and recycling B12 when there isn't an absorption problem, the release mechanism relies upon the same absorption mechanism that you use to get B12 out of your food so if that isn't working then very little is going to get back into your blood stream and most of it is just going to pass through you completely. So, if you have an absorption problem then you can no longer store B12 so it will need to be topped upregularly.

The symptoms of PA are the symptoms of the B12 deficiency it causes - huge overlap with other conditions and misdiagnoses as other conditions are quite common. Also, as PA is an auto-immune condition and many of the other conditions with overlap in symptoms are also auto-immune and auto-immune conditions tend to come in clusters it is perfectly possible to have PA and several other problem such as Lupus, thyroid, diabetes, MS ...


thank you. So very resourceful!

I truly do appreciate all the replies, insight and information :)


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