Pernicious Anaemia Society
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B12 makes me anxious and jittery

Hey there. On Nov. 02 I got my first B12 shot. Then sublingual 1000mu every day. Didn't felt much the first days. Then become tired, which I liked. Yes it was a warm, chilling, comfortable feeling. Stayed in bed all day, which I can, because I often work at home.

My physical symptoms improve constantly. Don't have all the wired tinglings and vibrations in the body nerves anymore. Or just very little from time to time. In addition my constant feeling of "inflammation" is greatly reduced. Unfortunately this is paralleled by a rise in anxiety and jitteriness over the last two weeks. Then the last two days were very hard. Like I'm in a constant state of anxiety and nervousness. Kind of, too much of an unpleasant energy.

Do others have/had that, too? Should I stop or give it a brake? Go to see the doc? My red cells count is normal, but homocysteine is to high and B12 was around 190 [unit].

If others have that, too would be good to know, how long this will last.

27 Replies

Hi Hidden It's not uncommon for some symptoms to appear to get worse before they get better and even for new ones to appear once the B12 you are taking starts to repair the damage done to your nervous system. Worrying and getting anxious will only use the B12 up for no benefit - you are not alone....

Do you know what your serum Folate level is? Folate is essential to process the B12


Thanks for the reply.

Don't know about my B9 status, yet. I did a DNA test at one of those companies, to check whether there are any genetic polymorphisms involved. For B9 its the famous MTHFR gene. Don't have the results yet, though.

I know that folate is essential in one of the two cycles that needs B12. The methyl-B12 cycle. The other one is the Adenosyl-B12 cycle IMO.


I used to get that jittery feeling for around 30 hours post-jab. Not any more.


Good to know. People tend to only complain in the beginning of the therapy, but then forget to write when they improve, later. Therefore its good to hear about success stories, too.


Hi AndreMurry. The high homocysteine and low B12 levels show that you definately have a B12 deficiency. Just wondering if your GP has tested you for PA (anti-IF antibodies).

And we're your folate levels tested (B12 and folate work together so,if,your folate is low, your do you will not be able to use B12 properly).

I'm a bit say you got your first shot, and then started using sublinguals...

Your GP should have provided 6 x loading doses and then injections every three months but if neurological symptoms are present you should have 6 x loading doses followed by injections every other day until no further improvement (sometimes for many months) and then injections every eight weeks (though this is not enough for some people - but that's another story). Not many GP's are aware of the neurological regime - if you need this and do not receive it, your GP is putting you at risk of potentially irreversible neurological damage.

Anxiety and nervousness is one symptom of B12 deficiency and it may be that you are getting this because you are not getting enough vitamin B12.

And as Clive alive says, when treatment begins, some symptoms seem to get worse before they get better (we hear this a lot). Also - recover takes place at different rates - it's very much an individual thing.

So....should you view of a diagnosed deficiency, no.

It would be well worth investigating whether you are on the correct treatment regime - you may need more B12, not less. And injections (if you haven't been prescribed the right regime) rather than sublinguals.

It's also worth noting at if you have autoimmune disease in the family then there is an increased possibility that you will develop an autoimmune condition - like pernicious anaemia.

It might be worth reading the PAS pinned posts to the right of this page when you lon on. These will give you lots of information about B12 deficiency, pernicious anaemia, diagnostic and treatment protocols, and the guidelines that are currently in place.

GP's are often very ill-informed about B12 deficiency and pernicious anaemia, and often fail to provide appropriate treatment, leaving patients at risk of permenant neurological damage and co tinted ill health. So, you may have to be prepared to challenge your doctor if you find you are not getting the right treatment. Many people here have experience that so it something we can help with, if necessary.

Please do post any more questions you may have...lots of knowledgable people here to help and support, if needed.

Take care and please let us know how you get on 😀.


I live in Germany, therefore the "Standard-Protocol" might be different. I don't know.

However there is no problem for me to get all the B12 shots I want. Right now, I just don't know if I can take anymore. Never felt like this before. Usually anxiety and nervousness is not much of a problem, so it must have to be related to the raise of B12, no to my previous low status. After all, catecholamines rise and that might trigger it IMO.

The doc is very good. He specialized on chronic fatique, inflammation and auto-immune diseases. He was the first after five years, that tested for Homocysteine and B12 and explained those two B12 cycles to me in detail.

The thing is, that my doc said, he could give me more shots, but he wants to wait until we know more about my folate system, after my DNA test returns. That's all.

But yes, the intrinsic factor test had not been done, yet.


Hi AndreMurry. Protocol may differ slightly in different countries, depending on which type of cobalamin is being used.

But the underlying principles are the same...if there are neurological symptoms present, the treatment with B12 injections should be immediate and intensive to avoid the possibility of potentially irreversible neurological damage.

B12 levels should be raised before supplementation with folate (to prevent the potential for further neurological damage).

B12 and folate work together so if folate is low then the body is unable to utilise B12 properly (but B12 levels should always be raised first).

Just so you are aware...B12 levels should be over 1000 for neurological repair to take place.

But perhaps you know this...😀

Good luck....hope your medic sorts you out quickly 👍


Thanks. I didn't know that B12 must be raised first and that it must be that high. Is this in the PAS pinned post. Have to read that first I guess :-)

1 like

Yep...good idea to read the pinned posts...principles will be the same wherever you are.

Information about the blood levels see 'Could It Be B12 An Epedemic of Misdiagnoses' by Sally M Pacholok and Jeffrey J Stewart or Martyn Hooper's What You Need to Know About Pernicious Anaemia and B12 Deficieny. Both definitely worth a read). Or do an Internet search... 'B12 levels needed for neurological repair'... (or variants thereof).

Worth trying google scholar for useful research papers on B12 deficiency.

Also check out - some good information there too.

B12 deficiency is a complex and tricky little monster 😖

Good luck and please post again if you need any further help or information.

Let us know how it goes 👍


Is there any scientific paper on the phenomena that things might get worse at first? Seems like everything I read is just anecdotal evidence...


not aware that anyone has actually looked at how people's symptoms vary after treatment - all the focus tends to be on levels of B12 in blood so quite probable that all there is is just a huge body of anecdotal experience.

You mentioned that you are taking sublinguals - are these methyl? some people do experience heightened anxiety as a result of taking methylated forms - may be related to COMT genetic variant ... so it might be worth trying hydroxo sublinguals - not so easy to find but they are out there.


No not methyl. As you said, I want to know my genetics first, before is think about combinations of meth-B12 and adeno-B12. I think if your folate system works fine, meth-B12 might be not optimal as not enough adeno-B12 is produced. Just a thought.

And what I can't figure out is: Is transcobalamin II even able to transport meth-B12 and adeno-B12? From what I understand B12 in the blood is useless. It needs to be transported into the cells by transcobalamine II... Therefore my (yet limited) understanding is, we need the B12 that is carried the most efficient by transcobalime II... This however is not a scientific fact, but just a thought.


transcobalamin is a group of proteins that bind to B12 to aid its transport - as such I would think that it isn't specific to a type of B12. there are actually three transcobalamins. TCIi is the group of proteins that are generated in the ileum to help with transportation from the ileum.

Most people don't have a problem converting methyl to adenosyl and vice-versa but there have been some reported cases of people who have had problems and are unable to convert methyl to adenosyl meaning that they either need both forms, or need to use hydroxo/cyano, which can be converted to both forms.


Hi Hidden I was "put on" cyanocobalamin 45 years ago when "Cytamen" was the only B12 injection available but when hydroxocobalamin (Neo-Cytamen) was introduced in the 1980s I suffered side effects such as headaches and skin rashes as well as nausea so went back to cyano and have continued on it ever since.

My then doctor gave me only a couple of years to live without the cyanocobalamin so I think it works.

The alternative to the injection was raw liver three times a day.... :)


mmmmH! Raw liver.... ;-)


That's certainly true. ...


whilst these responses are common in incidences of MCAD, MCAD appears to be a relatively uncommon disorder - much less common than B12 deficiency.

This article gives the estimated incidence of Mast Cell disorders - of which MCAD is one - at 1 in 150,000 of the population


Start a logbook of all your symptoms and assess a severity score. Start with day zero each jab and count from there.

There is a delayed reaction because the gut is involved. 3-48 hours typically.

The symptoms that arise from the jab repeat each time more or less in the same sequence.

Symptoms from food, meds and drink also have their own sequence. I.e. Wind, brain fog, tiredness, diarrhea

Once you recognize each sequence, you can anticipate the next symptom in sequence. For me, this gave me some control back as I understood how I reacted to B12 and in my case to gluten and dairy as well.


I thought the symptoms disappear over time. But ok, a log seems good advice.


It's like a roller coaster ride until you get your meds and supplements set correctly.


From my understanding, methylcobalamine is only necessary if you have MTHFR mutation that lower the production of MTHF. Therefore I will wait for my DNA results... Don't think cyano is that bad. Its basically hydroxocobalamine ionic bond to cyanide. And this little cyanide should be no problem when it comes to toxicity.

But I understand that its hard to stay on scientific grounds here.



Please refrain from telling people that methylcobalamin is the only form of B12 that works - it isn't true.

I respect that your experience and that of your family may be that methylcobalamin is the only form of B12 that works for them and that injection is the only method of delivery that works for them. However people are different and there are many posts on this forum from people who have experienced problems as a result of taking methylcobalamin and many on this forum who find that methyl actually does nothing for them.

Please note this article from the pinned posts regards use of methyl. Although it is addressing the use of sublinguals it also talks about methyl in general.


Whilst MTHFR variants affect the methylation process their main impact is on processing of folate. They make it less efficient. They don't stop it outright.

The best form of cobalamin and the best forms of delivery are the ones that work for the individual concerned. The metabolism of B12 is complex and not fully understood. The genetics are complex and the interactions of the various genes connected with B12 and methylation processes are not fully understood.

I think AndreMurry covers your issues with cyanocobalamin very well in his response to you. Some people do find this the most suitable form for them - clivealive being a case in point.



I want to give a short followup to my post:

Meanwhile its about 6 month since I got my first B12 injection. Allot has changed in my recovery and I can honestly say, that I recovered >90%.

Today I take a B12 shot every 3 months, as it is recommended by science.

The only thing that is still there is Tinnitus every now and then. But that is nothing, compared to the amount of hearing disturbance I had in the worst parts of the disease. For almost a year I had Tinnitus so bad, as if someone had screamed as loud as possible into my ear... These days it only appears, when I get a cold or did too much exercise ect.

Everything else is gone. The anxiety and jittery-ness was part of the recovery and subsided in a month or two.

During the worst few month of the disease, I had mild symptoms of psychotic-depression and paranoia. Thats went of very quickly after the first shot (during the first month of recovery) and is now all gone completely. Beginning numbness in my nerves: gone. No more pins and needles. No more disturbing somatic experiences. No more permanent flue like symptoms. Homocysteine is down to slightly above normal levels (~8 something I think). Weekly episodes of migraine, gone. Gluten, Milk, other wired nutritional intolerances, gone. Inability to do any exercise, gone ...

Every now and then, I get memory flash backs, thinking about the worst parts. It was like war. But even that is almost gone and not disturbing anymore. It became just a memory, like anything else.

I'm down to a B12 injection every three month. Taking more is bad for me, as I get a lot of pimples and spots in my face. Besides that, more B12 is not backed-up by any science and some posts here, where people are "megadosing" are plain bullshit imho.

Pernicious Anemia can trigger some psychic disorders, like somatoform disorders, which will not disappear from taking more B12! After such a disease, you have to reprogram your mind to let go of thinking that you are still ill, while you might have recovered already. That is a common weakness of human minds, I think.

And by the way, I had a genetic test and I have the 677 MTHFR mutation. Anyway, I think all the techniques to "help" here, are pseudoscience and I never took Methylfolate or methyl-B12 or anything. I'm a down-to-earth scientist and I can read statistics. There is no single paper that proofs any good for taking theses sublements.

Ok, thats it. I'm out of this forum, since I have to look forward. I wasted enough time with this fu***** disease.

Remember: My symptoms where so bad, if I could recover, you can to. At least if you really have Pernicious Anemia and are not just dealing with a psychic disease like a somatoform or anxiety disorder.

Just give it time and don't overdo the B12...

Good Luck...


Hello Hidden,

I even read your post, its wonderful to hear of your improvements. I just started taking methyl b12 sublingual and also have the same symptoms now (jitteriness and anxiety) as you had.I also ordered hydroxycobalamin sublingual to look if there is a difference. Which b12 type did you take sublingual?


Posts written by Hidden were written and posted by people who have since left the forum. There is no point trying to reply to the person.


I know this post is a year old but I just wanted to say I too have extreme anxiety and panic attack After having my b12 injection. Within an hour of having the injection I feel agitated and snappy. I also feel shakey and by the time the evening comes I am at panic attack level. It feels absolutely awful so even though my doctor keeps pushing for me to have the injections I’m too scared so I’ve been taking b12 tablets instead. The b12 injections also made me come up in painful spots on my face which have only just started to ease. I haven’t had an injection for over a month now and fatigue has come back I’m falling asleep a lot and feel very tired. My doctor thinks pylori (which o tested positive for) is the cause of my b12 deficiency, I am also D deficient too. I know my b12 level was 196 but I’m not sure about D she didn’t tell me. My iron was 115 (whatever tha means) I have struggled with iron deficiency anaemia on and off for years for which I’ve been treated with iron tablets but the b12 was only discovered recently by a locum doctor. I had been seeing my dr for a long time with gastric symptoms and fatigue, tinuttis, weakness, tingling in my feet, legs feeling swollen even though they wasn’t. I even had an echocardiogram for irregular heartbeats and breathlessness which came back normal. Dr let telling me it was anxiety related all of it. Thankfully a locum decided to check my b12. My doctor said they had checked it in Feb 2016 and it was 212 which is within normal range. I’m worried the pills might not be working but am also scared of this anxiety reaction from the injections. Anyone else had the same? Did it stop after a while? I keep thinking maybe the injections are too strong for me?

Anyway, sorry for the long post and I think I might make an appointment to discuss this further with my dr


To combat the anxiety from the b12, it might be helpful to try l-tyrosine and/or 5-htp. Get capsules and start with small amounts, pull open the capsules and measure out a small amount and let it dissolve under your tongue. Taken this way, results can often be felt within 15 minutes or less. If, say, 5 htp makes it feel worse then you might need the l-tyrosine instead or vice versa or both but in different quantities. Trial and error and record keeping is the name of the game. This can help keep your neurotransmitters levels in balance while the healing process takes place and make the whole process more comfortable, and don't be surprised if you have to adjust the levels of 5-htp or l-tyrosine as you heal.

Good luck and let us know how it's going.


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