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Pernicious Anaemia Society
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Do I need B12 injections or are sublingual lozenges enough?

Hi, I'm new here. I saw a news report recently about PA patients supplementing their NHS injections with stuff bought off the internet. When the interviewee listed her symptoms, it was like someone listing everything I had been to see my doctor about in the last few years. Looking at the PAS website I started to believe that I am also a sufferer. My gastroenterologist agreed to rest my B12 and intrinsic factor antibodies. B12 was 394 and IFA was negative. My GP was reluctant to offer B12 injections as a trial, despite into from PAS, so I started to supplement with sub lingual lozenges, using 3x1mg daily. Over the last month my symptoms have reduced; improved mood, energy, tolerance, improved thinking, memory, improved eyesight (no longer feel like I'm looking through dirty specs) and improved continence. Still have raging tinnitus and feel I have a long way to go before I can feel like I'm managing my life again, but I don't know what to do about asking for B12 injections again. GP now recognises that the B12 has caused improvement, but says I should just stick with the lozenges and shouldn't need the injections. I'm just wondering if I would see better, quicker improvement if I had the injections. What do others think? Thank you.

8 Replies

Hi SNEWEY I'm interested to know why you are possibly B12 Deficient.

Your level is not particularly low and you say you have benefited from the lozenges which suggests that you don't have an absorption problem via your stomach.

What sort of diet do you have? What other medications are you on?

Have you had your Folate level checked as this is essential to process the B12.

I'm not a medically qualified person but there are others on here who will be able to give you good advice.


Hi Clivealive, Thank you for your response. To answer your question, I am 60 years old, am hypothyroid, taking 150mg levothyroxine daily, my mother died of an autoimmune disease at 54, so I think the odds are stacked against me. I have a normal diet, certainly not vegetarian. The lozenges I am using are sublingual so don't get absorbed via the gut. I have not yet had my folate levels checked but will ask my GP to do that with my next blood test next week. The issue for me is that, although I am getting benefits from the sublinguals, I am afraid that is not enough and am concerned that without the injections, first of all, there is no official acknowledgement from my GP that I have a problem and secondly, I may not be doing everything possible to improve the neurological symptoms (specifically raging tinnitus).


Hi again SNEWEY I wish I knew the answers but whilst there are no "interactions" between levothyroxine and B12 people with thyroid problems may struggle with low levels of B12.

A quote from "Thyroid U.K." goes:

"People with an underactive thyroid or people with no thyroid cannot absorb this vitamin. A serious lack of B12 can cause mental illness, various neurological disorders, neuralgia, neuritis and bursitis. Some doctors believe the "normal range" of B12 is too low and that the normal range should be at least 500 - 1,300pg/ml (rather than 200 - 1,100)."

Your level of 394 is below that suggested threshold of 500 and with neurological symptoms I think the doctor should at least give you a "trial run" and go on from there.


"IFA was negative"

Page 29 of the "BCSH Cobalamin and Folate Guidelines" mentions Antibody Negative PA (PA where the IFA test is negative). Martyn Hooper, the chair of the PAS, tested negative more than once on IFA test before testing positive.

Page 29 is a diagnosis and treatment flowchart that shows the recommended process doctor in UK should follow with someone who is symptomatic for B12 deficiency.

Lots of b12 info .........



3) Pinned posts on this forum

4) Book "What You Need to Know About Pernicious Anaemia and Vitamin B12 Deficiency" by Martyn Hooper

5) Book " Could it Be B12" by Sally Pacholok and JJ. Stuart



7) BCSH Cobalamin and Folate Guidelines

I am not a medic just a person who has struggled to get a diagnosis.

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Hi Snewy. And welcome.

First, whilst your B12 level is not outside of the reference range, it is possible for some people to get the symptoms of B12 deficiency at anything under 500 (in Japan, people are routinely treated with B12 injections if their levels are below 500). For some people, bumping along at the bottom end of the reference range is not good enough. If you are having the symptoms of B12 deficiency, then you are one of those people.

Next - Intrinsic Factor Antibodies. This test is only accurate 50% of the time so you can test negative and still have PA (Antibody negative PA). Your GP may not know this.

And most GP's think that you can only have PA if you have macrocytic anaemia (enlarged red blood cells). Again, this is not correct.

As you have neurological symptoms (tinnitus - but you may have others) you should definately be treated by B12 injections. Again your GP may not know this.

So...first thing to do...print the symptom checklist on the PAS website (in the library section). You might be surprised to find that you have symptoms that you didn't even know we're symptoms. Tick all the symptoms that you have. You will see that you do have neurological symptoms and these need to be treated immediately with B12 injection to avoid potentially irreparable neurological damage. You can take this along to your GP.

Next...have a look at the PAS pinned posts - to the right of the forum page when you first log on. This will give you information about diagnostic and treatment protocols, together with current guidelines for treatment etc. In the third pinned post you will find a document complied by fbirder (Frank Hollis document), which gives a very useful summary of all the relevant guidelines, which will give you a quick way to identify what will be useful for you. Highlight anything that will support you argument for treatment with B12 injections.

You can then take the symptoms checklist and the highlighted documents along to your GP for discussion. Again, as you ha e neurological symptoms, you should push for treatment with B12 injections.

The golden rule is: treat the symptoms, not the blood results (as in NEQAS guidelines in the pinned posts - your GP may not be aware of this alert but should certainly read it).

B12 injection regime: for deficiency without neurological symptoms, the regime should be 6 x 1mg Hydroxocobalamin every other day (the loading doses), then 1mg Hydroxocobalamin every three months.

However, the B12 regime for deficiency with neurological symptoms is: 6 x 1mg Hydroxocobalamin every other day (the loading doses), then 1mg Hydroxocobalamin every other day until no further improvement (this may be many months for some people), then 1mg Hydroxocobalamin every eight weeks. Not many GP's know about this regime!

Your GP can find information about this in his prescribing bible (the British National Formulary or BNF). He has a copy on his desk and can look it up while you are there. But he may have to read further than normal - it's the second paragraph down 😀. Note: your GP may say ah ha, but you don't have macrocytic anaemia - irrelevant - neurological symptoms are present in approximately 30% of patents who do not have macrocytic anaemia.

So...your GP says you shouldn't need injections! Well, many GP's are extremely ill-informed about B12 deficiency and PA. I hope that once you have read the PAS information and prepared the highlighted 'stuff' for your GP, you'll have the confidence to know that he should be treating you with injections and argue your case. Don't be surprised if your GP becomes a little hostile - many do as they don't seem to like it when patients appear to challenge them.

And while I'm here, just a couple of other tips:

Your GP should check your folate levels. Folate and B12 work together so, it your folate is low, your body will not be able to utilise the B12 properly. Folate levels need to be in the top third of the reference range.

GP's often say blood results are normal when they are not. It's a good idea to get print outs of all your blood results so that you can see for yourself. If you need help with interpretation, post them here and folks will help.

Also a good idea to have serum iron and ferritin checked - if you have gastric problems, iron levels can be reduced and this will make you feel very ill indeed. Ferritin levels need to be 80 - 100.

I seem to be getting quite long here so rather than list them, please could you see see the pinned posts and or do an internet search to see the potential causes of B12 deficiency. Most often it will be an absorption issue but there can be other causes - so worth looking at to see if you can identify if anything applies to you. Any your GP / gastrologist should be trying to identify why your levels are low enough to give you symptoms.

And last - but not least. For anybody with an absorption problem (the most common reason for deficiency) B12 tablets will not work - since the body cannot absorb them. Sublingual tablets are slightly different because they are absorbed directly into the blood stream (they by-pass the stomach). They work for some people, but not for others. Most people tend to use them to top up between injections. They are not recommended for the long term treatment of B12 deficiency - especially where neurological symptoms are present (except in rare cases where B12 injections are not well tolerated). Some people also get relief from B12 nasal sprays or patches.

So finally, if your GP has recognised that treatment with B12 has improved your symptoms he has implicitly recognised that you need treatment with B12. All you need to do now is focus on the presence of neurological symptoms and give him the guidelines and evidence to support you request for treatment with B12 injections. In light of the evidence (evidence based practise) insist if you have to 😀).

Please do post again if you need any further help or support. Lots of people here to,pop along and help, if needed.

Take care and please let us know how you get on X

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Well, I followed the advice, gave my doctor the leaflets and Martyn's book and your response. She has tested my B12 again, after using the sublinguals its now up to 694. IFA and PCA tests come back negative and on the FBC everything is within normal ranges. Using 2x 1mg a day for the last month my symptoms improved; brighter vision, quicker mind, better memory, hugely improved continence, but still raging tinnitus. Doctor agreed to do a trial for 6 months, but when I went for my first injection today was told that the 'trial' was 1x1mg every 12 weeks, no loading dose. Nurse told me that because all tests came back negative loading dose was not necessary. Very disappointed and a bit scared. Feel like I'm being humoured. I'm imagining after six months doctor saying, "Well it made no difference so there's no need". Mention of 'treat the symptoms, not the blood results' has been totally ignored. Not sure how to proceed from here. Will continue to take the sublinguals, but not sure that is a long term solution. Would be grateful for any advice please. Thank you.

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Personal opionion: there has been so little research into other means of delivering B12 and people respond so differently to different ways of treating that it isn't really possible to say if injections would work better for you.

Within my family - my mother and I have been diagnosed as having B12 absorption problems and treated with injections. For both of us this seems to have kicked off a reaction that means we need to keep our B12 levels ridiculously high in order to function. My brother and aunt are both highly symptomatic of B12 deficiency and treat themselves with nasal sprays at much lower doses. I only really started to recover when I started using nasal spray frequently and although I do also self inject and get shots from GP (as much to keep it on my records as anything else) I find that if I have a shot in the morning then I'd be turning into a grumpy old so and so before the evening unless I was using the nasal spray. However, that is anecdotal rather than rigorous scientific evidence that injection may not be the best method for everyone.

The other thing to consider is the form of B12 you are using - most sublinguals are methyl but you can get hydroxo sublinguals so another option would be to try a different form of B12.

What should ideally happen is that the treatment you receive should be tailored to what works best for you which can be very different from the standard treatment. studies have shown that high dose oral can be effective but they have also shown that it doesn't work for everyone. Unfortunately the only formal treatment recognised in the UK is injections where there is an absorption problem ... some GPs have pushed high dose oral on the basis that it worked in studies (whilst overlooking the fact that the studies showed it didn't work for everyone. What isn't happening is listening to the experience of patients and responding to that.

Which is a long way of saying that personally I don't think there is a precise answer to your question. There is a general answer - that injections would normally be the best solution - but no way of knowing if it is the best solution for you as an individual.


Hi Snewy. I agree with everything that Gambit62 says...it's obviously a very tricky and individual thing.

Here's my thinking...

The reason for loading doses is to raise deficient or low B12 levels quickly.

So...although the thinking behind not giving loading doses is a bit 'wrong headed' the position has become confused because the sublinguals have raised your B12 levels - to a point where if you first presented with these B12 levels, any GP would be very unlikely to consider B12 treatment as an option (most will be completely unaware that people with apparetly 'normal' B12 levels can still present with deficiency symptoms).

And, just so you know, a negative IF test is only 50% accurate - you could still,have PA - although your nurse seems unaware of this.

In your case, the sublinguals seem to be raising your B12 levels and you have seen some improvement of symptoms (albeit the tinnitus is still a problem). This is good news because it shows you are responding to B12 treatment. (Not everybody will respond to sublinguals in this way - as gambit62 says).

As your B12 levels are rising the 'work' of the loading doses has been partially done - 'cause your levels are no longer deficient or low and more importantly, you are seeing improvement in your symptoms.

If this was not the case, and your levels were still low or deficient, I think pressing for the loading doses would have been the thing to do.

As the position is now, a trial of three monthly injections is perhaps one way to go....your levels are rising and the injections will push them up a bit further - and symptom relief should continue and hopefully improve further.

The most crucial thing here is assessing your symptoms on an ongoing basis....your symptoms should continue to improve and you should not experience a return of symptoms prior to injections (for some people, symptoms creep back just before an injection is due, a sure indicator that more frequent injections would be of benefit).

On the other hand, some in this position (with levels and health improving) could equally choose to stick to sublinguals and assess symptoms, again on an ongoing basis.

With respect to the trial issue - well, if you can demonstrate that the injections (if this is what you choose) are working for you (perhaps by keeping a symptom log to show your GP), then there really should not be a problem with your GP continuing them. Especially as you presented with neurological symptoms.

If you get 'break-through' symptoms before each three monthly injection is due, then because of your neurological symptoms, you could go back and argue for the eight-weekly neurological regime.

And if you have injections but still have to top-up with sublinguals to keep going then, again, more frequent injections would perhaps be of benefit.

And if you go for sublinguals alone....they may continue to work for you...or they may not.

All the current guidelines recommend B12 injections for those with neurological symptoms. Whether these change in the future remains to be seen. It's just a shame that your GP didn't start you on injections when you were initially diagnosed 😖.

Unfortunately, there isn't one 'correct' answer here...just a range of imperfect options. It's all about an individual's response to B12 - what suits one might not necessarily suit another.

Good luck with whatever you decide to do, pop back with questions if you have any, and let us know how it goes.

Here's to improved good health 👍


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