Pernicious Anaemia Society
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PA, deficiency and anxiety

Hi. I'm new here. I've had about four major episodes of anxiety and depression in my life. I'm 38 and just recovering from the fourth.

All have rendered me unable to work in the time I was ill.

I was recently diagnosed as b12 deficient due to my body destroying intrinsic factor and had a high level homocysteine. Had also been anaemic. And each time that I've had the anxiety/depression episodes it's been accompanied by a tingling/itching at an isolated point under my foot. Almost painful. I also have some thyroid issues I'm still being tested for. Hyperactive.

Other symptoms have been tiredness. Weight loss. Dizzy ness. Foggy head. Being in a bubble. Loss of appetite. Difficulty sleeping.

I initially had one injection of hydroxocobalamin at 1mg. And it did seem to help me in the week following it. But then anxiety kicked in again as I was nearing my period. Enough to make me start on the antidepressant sertraline which I've taken before.

Antidepressants are now understood to help growth of damaged nerve cells in the brain.

New blood tests 5 weeks after initial injection didn't show much improvement. So had a second injection of 1mg.

So my question is -

Have any of you had severe mental effects from pa and b12 deficiency? Or is it likely that the anxiety and depression when severe like this are caused by other things?

Also does anybody have experience with how much to inject? I've had 1mg, followed by another dose 5 weeks after.


18 Replies

I had over 4 decades of depression and anxiety before I was diagnosed with a B12 deficiency a couple of years ago. Both continued to get worse - along with loads of other things like loss of balance - over the 15 months after being told my B12 was low and it was only when I gave up on the doctors who seemed to have no understanding whatsoever of what B12 really was and how it worked that I actually started to get better.

I generally use a nasal spray, and started taking 3-4mg a day which was my turning point. Balance was good enough to be happy at the top of a ladder pruning a grape vine a few weeks later and I was a bit surprised to realise a couple of months later that the depression had gone and the anxiety was much less.

I still notice mild anxiety around periods - and if I'm on the ball realise that means that the period is coming (along with headaches and water-retention. Don't know if anyone has ever done any research on interaction between hormonal changes and B12 but I suspect that you need more when the hormonal changes happen - hence the recurrence of problems.

In relation to high frequency doses you might find this post interesting

People vary an awful lot in how they respond to B12 - what doses they need, how frequently and even which form of B12 suits them best. I use a mix of hydroxo and methyl (mainly nasal spray but do inject some hydroxo sub-cutaneously). Hydroxo helps me best with the neuro-psychiatric and methyl with the neuro symptoms themselves.

Would be interested to see the research on anti-depressants helping to heal cells in the brain - my understanding was that they are generally addressing chemical imbalances so just curious. They didn't really do an awful lot for me.

In UK the guidelines (not particularly good but ...) are hydroxo every other day for 2 weeks followed by maintenance every 3 months. In Germany maintenance is every month. If you have neurological symptoms - eg the tingling - then it should be every other day until symptoms stop improving followed by maintenance every 2 months ... however some people need a lot more than that. Know I do.


Thanks so much for all this. It's nice to hear similar stories and how other people have coped.

Yes new research on antidepressants show that it is not the chemical imbalance it levels out as previously thought but the subsequent boost of neurogenesis in hippocampus.

Depression and anxiety seem to happen when the degradation of nerve cells are greater than the rebuilding of them. And hence hippocampus shrinks.

And isn't that exactly what happens when you are b12 deficient? The nervous system is not restored due to a deficiency?

I would ideally like to be off the sertralin and thinking it might also mask the neuro-psychiatric symptoms of the b12 deficiency. So hoping when all is in balance I can taper out.

Due to the fact I can't absorb b12 from the stomach because of the autoimmune condition I suppose I have to always have injections - and not nasal spray or pills.

It does seem like I've been given too little when I hear what you guys are saying and the guidelines. So let's see what the GP says when I see them next week.

Thanks again


The malabsorption relates to absorption in the ileum. The idea behind sprays is that they get absorbed through another membrane - eg tongue in case of sublinguals or nasal passages in the case of nasal sprays - so don't rule those out. Pills can sometimes help as 1% of B12 is absorbed passively (ie not through the ileum) and that may not be affected by the absorption problem you have.

Intresting about the hippocampus - which does seem to play a key part in anxiety and depression - as much because a loop that should shut down doesn't seem to shut down, so normal calming mechanisms stop working - would say that that was definitely a key element of what has been happening for me.

Unfortunately the guidelines in the UK aren't very generous with treatment - which is a bit stuipd is it leaves residual problems that then cost more to treat. I really do not regret treating myself - I felt so at the mercy of ignorance and was so scared of having what little B12 I was receiving taken away. HOwever, I'm lucky I can afford to treat myself ... and it's the unfairness that that brings that really gets to me.


That's great to know about the spray and pills. Thanks so much.

It really does seem like a condition one has to take responsibility for on your own in order to get the right treatment.

I'm sure I'll be back here with more questions ;)


I'm so sorry you are having these problems Nadpa and you are quite right - it looks as though you have been vastly under treated, as all the signs (high homocysteine, anaemia, etc.) and symptoms (weight loss, insomnia, fatigue, etc.) seem to indicate severe B12 deficiency due to absorption problems caused by the autoimmune response to the intrinsic factor. Autoimmune thyroid problems and PA are interlinked and their symptoms often overlap (four in our family have autoimmune disease).

My relative (also hypothyroid, and vegetarian/vegan with ME for many years) had severe B12 deficiency with anxiety, hallucinations, paranoia, memory loss, etc. Her GP took no case history and refused to consider B12def. An MRI ruled out Altzheimer's, and she was then misdiagnosed with dementia and prescribed psychiatric drugs. The family had a long, drawn out battle to obtain B12 injections (now monthly) and she made a remarkable recovery, except the long delay meant that she may never fully recover her memory.

You probably already know that there are BCSH, UKNEQAS and NICE guidelines. BNF also advises that patients presenting with neurological symptoms, which you have (foggy brain, tingling foot,anxiety). should receive 1000 ug i.m. on alternate days until there is no further improvement. It is appalling that your GP is ignoring expert advice and risking catastrophic nerve damage Have you tried writing to the surgery or asking for another GP at the same surgery? This site has information and advice on writing with useful templates:

(In case you haven't seen it, the excellent film on this site explains why it is essential to treat quickly and adequately as there is a short window of opportunity before neurological symptoms become irreversible).

This latest BMJ research document also gives up to date guidance on treatment. It might be worth enclosing summary with the letter (in case GP will not read the complete document) to underline the seriousness of delaying adequate treatment.*** I sometimes think if they see things set out in writing, they are less likely to ignore it (they are also afraid of being sued I'm told).

Cmim/BMJ document. " Summary:

* Vitamin B12 deficiency is a common but serious condition

* Clinical presentation may not be obvious thus leading to complex issues around diagnosis and treatment.

* There is no ideal test to define deficiency and therefore the clinical condition of the patient is of utmost importance."

* There is evidence that new techniques, such as measurement of holotranscobalamin and methylmalonic acid levels seem useful in more accurately defining deficiency.

* If clinical features suggest deficiency, then it is important to treat patients to avoid neurological impairment even if there may be discordance between test results and clinical features.

Severe deficiency shows evidence of bone marrow suppression, clear evidence of neurological features and risk of cardiomyopathy.

It is important to recognise that clinical features of deficiency can manifest without anaemia and also without low serum vitamin B12 levels. In these cases, treatment should still be given."

***"If there are neurological disturbances, then treatment should be expedited and started without delay - 1,000 u.g. i.m. on alternate days. This should be continued for up to three weeks or until there are no further improvements.

In irreversible cases, e.g. P.A., the treatment should be continued for life. "

I hope you are able to get the more frequent injections you need Nadpa but, in any case, there are many people on this site who can advise on self injections and/or supplementation with nasal and oral sprays, etc.

1 like

Thanks so much for all this information!

It really feels good to be understood and see that there are others out there.

I didn't know about the guidelines so will check those asap.

And then get a proper plan laid out with my health practitioner.



I hope these links work:

Re. "risk of cardiomyopathy" in the BMJ summary above, it is very high homocysteine caused by low B12 that increases this risk - another reason for more frequent treatment.


Thanks! Great with some solid Scientific texts.

All links worked except the online one.

Yes there are all sorts of risks with too high homocysteine.



hi nadpa. so sorry to hear ur having such a dilemma getting proper diagnosis/treatment from the medics. the replies u've had so far, comprehensively cover, the b12 info. so i'll just post my experiences of b12 d in respect of anxiety etc.

prior to the b12 intervention i had severe anxiety & black depression. it took some time for the b12 to kick in as i think i must have been v. depleted. i opted for the SQ route of 0.5 mgs/mls on alternate days, until my levels seemed replenished. i then went to one monthly SQ injections. more recently, i've had to play it by ear as to how much & when i need the injections. it tends to vary with what's going on with me.

at the point where i felt my stores were replenished, and when i felt i needed a b12 top up, i often got a brief exacerbation of the background anxiety back, post the injection. i' ve manged this by adjusting the dose & it seems to work. as others have commented, b12 treatment seems sooooooooooooo individual to each person. after a while u'll get a good understanding of when u need to top up & by how much. it becomes instinctive after a while. hope that makes sense.


Oh so lovely to hear there are others who have had the same symptoms. Though of course sorry to hear you've had to go through it. It is living hell.

What is SQ?

I understand what you mean about an intuitive feeling. Makes sense.

I hope that I'll be able to get off the antidepressants for my anxiety once my b12 and homocysteine balanced out.

but seems like it's a delicate balance to keep. Knowing your body's needs.

Thanks again.


hi Nadpa. no, ur not alone Nadpa. SQ means subcutaneous - an injection into the fatty layer of tissue (pinched up to give the injection) under the skin, rather than IM (intramuscular) into the muscle.


Ah I see. Thanks.

So many new things to learn ;)


Always known as a happy, positive, enthusiastic but balanced individual, the only times I have felt down in my life, despite some grim things I have had to deal with on occasions, have been when I've had B12d symptoms. This year, as my symptoms have increased, I have found the mental resources I have built up over the years just haven't been available to me in my head to cope with bad situations which has been really disconcerting: it's hard knowing my behavior isn't being logical any more! It's made me question who I am and I've found I've wanted to take on paranoid answers, rather than sensible ones!

My Mum has suffered from severe depression throughout my life and as a consequence I am "not a fan of!!!" suicide as an option for anyone, knowing how it affects those around the sufferer BUT at times over the last few months when my symptoms have been bad I have craved it! As I have tried to get a balance of B12 medication I have been on a roller coaster of insidious, hideous psychosis and feeling OK and knowing that's all it is! It's a weird feeling like I'm looking from the inside one moment and the outside the next but it has enabled me to see the effects of B12 on my psyche very clearly defined.

(Having seen the PAS symptoms list I'm sure my Mum has long been B12d but she currently isn't communicating with me again, following an increase in her symptoms earlier this year. I will try to help her somehow.)

Huge thanks to Gambit, Sleepy bunny and everyone else here for all your help. I am now getting a level of treatment that is enabling me to be well. I've still got to get it balanced for the long term but at least now there is the prospect of a long term and I'm looking forward to having a life again!

I wish more people would push for more treatment to try to be as asymptomatic as possible. I think there would be a great improvement in the quality of life for so many if only they had symptom-tailored dosing regimes.

Good luck everyone: go for it!

1 like

I'm so glad you're getting more treatment and feeling much better Denise.

B12 deficiency is involved in DNA and one of the problems seems to be that it affects people in different ways. Looking back, it has made sense of a lot of what has happened in our family - my mum came to this country before the war to escape poverty - she'd had rickets as a child, rarely had meat and died early of breast and bone cancer. Looking back, I realise now that she was anaemic, had blood transfusions, was so obviously B12 def. and probably even more depleted after having three children.

One of the hardest things has been convincing everyone from GP to family and friends that anything from depression to paranoia and hallucinations was down to a simple vitamin deficiency - everyone seemed to go into complete denial, making it so hard for my sister to be understood.

Martyn Hooper, In his book, cites the horrifying case of a lady with PA, receiving injections for years. A new GP stopped her injections. She then became very ill and ended up in an asylum. Luckily a friend contacted him and he managed to intervene on her behalf.

Very best wishes to you and your mum.


Thank you Polaris! It's terrible how much some people are unnecessarily suffering and feeling so limited in what can be done. At least helping here is good. Best wishes, Denise


Thanks so much for your story. It sounds tough and glad you're feeling the effect if treatment now.

So b12 injections alone helped you out of the depression / psychosis?

That is good news!

I fear I'll be reliant on antidepressants forever.

And it's obviously a bit confusing whether I'm getting better or not with as I suspect they mask some of the neuro-psychiatric aspects of the b12 deficiency.

Good luck to you too! :)


Reply to "I initially had one injection of hydroxocobalamin at 1mg. And it did seem to help me in the week following it."

You should have received 6 loading doses each 1 week apart.

You sound like you need to be on more frequent injections.

Do you take folic acid?

Do you keep a log book of all your symptoms, when they occur, along with medications, food , drink and behavior which may cause the symptom albeit with a time delay due to the gut being involved?


Thanks for your reply.

Yes it does seem like I should've had lot more frequent injections. I will ask my doctor about it next week.

I did start taking folic acid cause thought that might help. But have now read that that can falsely take down the homocysteine making it hard to read from b12 alone if I'm deficient or not.

I haven't kept a log. But that's a good idea! Thanks.


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