B12 deficiency - reaction to B12 injections???

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Hi, in the past few weeks I have been diagnosed with B12 deficiency anaemia.  Some of my results are:

Iron - 9 (ok level: 12)

Folate - 4 (ok level 4-8 i think; my GP says this result was fine)

B12 - 118 ('normal' level 200-900)

These are from an English GP.  I have been tested for coeliac disease (blood test was negative) and awaiting PA antibodies result.  I have been referred for Crohn's.

I have started on B12 injections - 6 every other day or so.  I have had 4.  After injection 2 and 4 I have woken up the following day with intense pain across my lower chest/upper abdominal area; such pain that I can hardly move around, accompanied by nausea and a hot, itchy, red blotchy rash on my face and little raised lumps along the underside of my forearms.

As my B12 level is so low, I am keen to finish this course of injections.  But do you have any idea whether these are side effects or an allergy.  I have read through literature about side effects, I think that's what they are but are they serious ones and mean I should stop?  I see a different nurse each time for my B1

If I am taken off B12 injections, how on earth do I improve my B12 level?  I am not a veggie/vegan and eat plenty of B12; I have bowel/digestive issues that we think are leading to malabsorption.

I am mid-30s and have had bowel problems and fatigue all of my life, more recently I have had tingly and painful feet, dizziness, migraines and possibly signs of memory impairment.


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  • Posted

    I too had 6 injections on alternate days for the anaema, and am told I'll need an injection every 12 weeks for the rest of my life.

    but my side effects are numb fingers and hands every night, more forgetful than ever and palpitations.

    nothing to worry me unduly. 

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  • Posted

    Did the gp start you on injections are you talking folic acid, why do they say fine whe your folate is under range xx
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    • Posted

      Thanks jazzyanne.  The GP started me on a set of 6 B12 injections over 2 weeks.

      What blood tests relate to absorption of B12?  

      As for folate, I agree.  The first time I saw her she said I had iron deficiency anaemia, b12 deficiency anaemia and folate deficiency anaemia.  She started me on a course of ferrous sulphate and B12.  I thought later, hang on, maybe i should also be on folic acid.  I asked her about this a couple of weeks later but she said that level was normal so i won't have to supplement.

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  • Posted

    Hi Sazmaz.

    so sorry to hear you've had this condition for solong  without diagnosis/treatment.  it's such a debiltating condition and so  easily rectified  when diagnosed/treated.

    re; the 'side effects': frequently  people have ''nerve wake up'' type symptoms post commencement of treatment.  the symptoms  temporarily get worse before getting better. it's  the 'kick start' of  the nerve healing process.

     skin rashes are also a frequent  response for people. it's understood that once the body starts to work  more effectively, it  gets rid of the end products of metabolism (toxins/gunge/homocysteine  etc) more efficiently  through the eliminatory organs.  the skin in this instance.  

    it's possible also that the sudden flooding of the body with b12 causes it to react this way.  once the body acclimitazes to the b12 the side effects may well settle down.

    re: the symptoms in your last paragraph.  they are rather typical of b12 neurological symptoms & should get better with treatment.

    re: if you're taken off the b12 injections, there are many other routes by which the b12 can be administered & absorbed - 1) sublingually 2)nasally 3) patches etc. have a look on Amazon.

    however, having said that, i'd consider it prudent to have the abdo/chest pain checked put by the Doctor, to rule out any other more acute causes. 

    re:   the low folate & iron.  these 2 are interdependent with b12.  both need to be in the UPPER levels of normal to ensure the b12 is properly metabolised & utilised.   unfortunately,  GP's are very poorly versed on the treatment of b12 deficiency, so you may need to self-supplement if they refuse to prescribe iron & folate.     

    sazmaz, there's excellent information available on the Pernicious Anaemia Society (PAS).  also, the the website ''HealthUnlocked'' have EXCELLENT info. and people on there are also very supportive.

    all good luck with the treatment. hope it goes well for you and that you begin to feel the benefits soon. however, it may well take some time to experience the full benefits.


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    • Posted

      Hi Caitlin, thanks for your reply, it means a lot.

      I am at least grateful my doctor thought to test for b12, otherwise i would still be in the dark.  Thanks for the tips about recovery, which I think will be slower than I thought, I guess the body takes a while to heal.  

      I watched an excellent documentary on youtube called 'Diagnosing and Treating Vitamin B12 Deficiency', you have probably seen it.  But it did hit home how serious this can be.  When Sally Palochok talked about a lady with psychosis whose B12 levels were severely low at 120, I realised how serious my low b12 level was/is. 

      I honestly thought I was a naturally lazy person who just did not have the get-up-and-go of other people.  In my early teens they nearly diagnosed me with ME, in the end Chronic Fatigue Syndrome (which incidentally the medical profession insinuated was all in my head).  I couldn't even get up out of bed, my mum had to carry me up the stairs.  Even now, up until I started on iron and the injections, I had to sit down after climbing a flight of stairs, due to lightheadedness and weakness in my legs.  I never told anybody because, again, I just thought it was my own fault, being unfit.  It is weird how it is slotting into place now.  I just wonder what it causing the malabsorption as now it doesn't look like PA as my test just came back negative.  

      As for the folate, i think i will start on that too.  

      Thanks so much for the PAS and HealthUnlocked info; I'll take a look.

      It was very kind of you to take the time to answer, this is all so new to me so I appreciate any help or just a 'hang in there, it does get better'!

      All the best for the festive season, S

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  • Posted

    Just to keep this updated, I have now been taken off the B12 injections due to my reactions and will have to meet my GP in 2 weeks' time to discuss the symptoms.  All of the medical professionals I have seen have never encountered any side effects/allergies  with B12 (I have seen 6 in the past 2-3 weeks); I know they are super busy and very educated, but this has been an eye opener,

    I have read quite a bit around this.  Something of concern is that a number of my symptoms relate to anaphylaxis, whether there are other ingredients in the injection that are causing this i don't know.  I have seen online that benzyl alcohol has caused similar physical responses, but no clue whether this is in the injection.

    Honestly though, every allergy test I've ever done I have had some reaction to, to some degree or another, from dust to animals to penicillin,  so I would not be surprised if something seemingly innocuous like a b12 injection is rejected by my body!

    Thanks all for comments.

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    • Posted

      Crohns is most commonly found in the Terminal Ileum (last part of the small bowel) and that's also where B12 is absorbed. So inflammation there is very likely to cause a B12 deficiency. 

      It's hydroxocobalamin we get in the UK because they can get away with less injections that way. The proper stuff is methylcobalamin; perhaps they can get hold of that instead if that is the problem. Or as said you should still be able to absorb some through strong enough pills or lozenges.


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    • Posted

      Hi  Sazmaz.

      if you have any difficulties breathing;   wheezing, swoolen mouth/tongue/throat/sudden swallowing difficulties etc.  in response to the b12 injections, your GP needs to record this in RED In your notes. 

      from what you say, it sounds that your body is highly sensitive to anything 'foreign' and over reacts. severe reactions to b12 are, however, rare. there's likely to be preservatives/ alcohol etc in the b12 that you maybe sensiive to. 

      i've read in other B12 D forums, that some people are unable to tolerate the 1 mg  injection on alternate days. however,  some can manage  the 0.5 mg weekly or  twice a week very well.  therefore, the B12 ''loading'' dose gets spread  over a longer period of time. 

      also, the IF (Intrinsic Factor) and anti-body tests for Pernicous Anaemia (PA) are very unreliable. they frequently yield false positive & false negative results. some Haematological experts suggest that one can  only be conclusively sure,  when  3 consecutative test results are either positive or negative.

      Sazmaz, i think you should suggest to your GP,  that you get referred on to a Haematologist in respect of your b12 deficiency.  sadly, GP's, know VERY little about the vagaries of B12 d. their training includes just a few hours in nutrition. GP'sjust 'blunder along' treating ''paper'' results when it comes B12D.  this is an incredibly individual specific  condition.  everyone responds differently to treatment.

      i do hope, you feel better now, that you know what the problem is.

      have a good x-mass


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  • Posted

    An update from me, who started this post...

    I have had a gastroscopy and endoscopy, which came back clear.  So ruled out Crohns and coeliac.

    However, quite a big development - I have been in agony the past couple of weeks, with similar attacks to what I described before Christmas with the severe chest/upper abdominal pains that I had after the B12 injections.  New diagnosis: gallstones and cholecystitis.

    When you read about gallbladder disease you can see that many symptoms I have been having for years: upset tummy (nearly passing out when going), reactions to food after eating and the chest pain (like a heart attack and it's true, as bad as labour pains!) could be explained by gallstones.  The fact that the foods that contain B12 (milk, cheese, meat etc) are what cause my gallbladder serious problems and for me to have awful upset tummies, could this also explain why I am not absorbing enough B12?

    I don't know is the honest answer, but I have been hospitalised twice in the past 10 days with gallbladder attacks and severe abdominal pain.  I need my gallbladder removed but I may have a wait for several months!  I am at the stage now where nearly anything I eat (I have cut out wheat, gluten, dairy and sugar since March and now I know about the gallstones, fat too!) is causing symptoms and pain but the good old NHS will only operate once i return multiple times to A&E (I am at 2 visits, that's not enough) otherwise it's a waiting list of possibly several months.  I am self-administering oral morphine at home until then.

    So I cannot eat hardly anything and anything I do eat causes serious pain, I have a full-time job and children but my case is not urgent until something really goes bad like I turn yellow, the gallbladder perforates etc :-(  

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