Hot burning feet after B12 Injections of Cyanaco

Hi to All, I have had small fiber peripheral neuropathy for a bit over 2 years. In April 2014 my B12 level was 515, in October 2014 was 320, in March 2016 was 280). So in March 2016 I started stressing and decided to get to the bottom of my lagging (but not painful) neuropathy. I went to a new neurologist, many new tests, etc. The only problem found so far has been B!2 deficiency so I received 4 consecutive daily injections of 1000mcg B12 Cyanacobalamin (bad idea, take note everyone!). My symptoms worsened dramatically after my 2nd oe 3rd injection - from simply pins & needles & wrinkly socks sensations (that I had for 2 years) to hot feet flaring feet especially at night in bed (a nightmare with no sleep). I must also admit that during this period in March 2016, I started worrying which lead to anxiety, which I still have not been able to control). Can anyone PLEASE explain/write/share your thoughts or experience. Thanks much.


PS - is there a better site online to post my condition?

25 Replies

  • Hi, I've pernicious anaemia 18 year's of treatment now. Yes I've had the burning feet but saying that I've had it with my hypothyroidism also. Anyway I found that in the beginning of b12 injections the symptoms got worse, however I continued to have more b12 injections until I was 2000 plus , swimming in b12 and it went. It's just the b12 waking up the nerves ,and healing them. You need more to get this problem sorted. It can only get better with more. B12 won't harm only help.

    P. S  Try hydroxocobalamin or better methylcobalamin. They are better and last longer.

  • most people retain hydroxocobalamin longer than cyanocobalamin - but there is significant variation.

    methylcobalamin works for some but not for others - this may be because the body needs two forms of cobalamin - methyl and adenosyl - but some people aren't able to convert methyl to adenosyl.

    whilst the two are better for some people it is a generalisation.

  • Thanks much Elizzajoe, You have just given me some Godly sent hope! I remind you that my 4 injections were done April 2nd through 5th which is just over 1 month ago! Should I continue taking my B12 2500mcg Methyl sublinguals? I stopped because my primary care Dr. (not my busy unreachable neurologist!!) told me my B12 jumped over 1000 only 2 days after I stopped the injections. Assuming my elevated symptoms (burning feet, calfs, more wrinkly feet) are due to the injections, how long do you guess before they call down?

    Important PA question: My "Gastric Parietal Cell Antibobody, IgG" is 1.3 units. Does this mean that I surly do not have PA? Are there other necessary tests to conform this?


  • from 


    Dr Chandy is excellent  

    IN United kingdom. 

    B12 deficiency (PA) with neurological signs and symptoms. Initially hydroxocobalamin (or

    methylcobalamin) 1mg on alternate days until no further improvement (maximum reversal of neuro-

    psychiatric signs and symptoms are achieved), then 1mg every 1 or 2 months. *Clinically review every 2

    months with or without serum B12 and if clinically indicated increase the frequency to every month or

    more frequently

    Note: treatment should be tailored to patient need; some people need injections more frequently than

    once per month.

    Prophylaxis of B12 deficiency for specific medical history and patients presenting with moderate or severe

    symptoms but may not have low blood serum B12 (‘subtle’ B12 deficiency): 1mg hydroxocobalamin or

    methylcobalamin IM or SC alternate days for 6 doses (2 weeks), then 1mg IM or SC every 1-2 months:

    review and increase frequency to minimise the development of symptoms

    Oral B12 treatment may also be offered for mild deficiency, and where a B12 deficiency has been

    demonstrated through a therapeutic trial but absorption of B12 from the gut is normal (ie no autoimmune


    2 methylcobalamin is used in USA, Canada, India, Japan and other countries. Pharmacists in Wales also report that

    they can prescribe methylcobalamin. Methylcobalamin is considered superior to hydroxocobalamin by many people

    because it is one of the natural body forms of B12

    P.S Just ask your doctor straight do you have pernicious anaemia. 

    I was told I had parietal cells for pernicious anaemia and at that time my b12 was 140. I felt like I was dying. Now after treatment I'm a new women. I keep on top of it. All is well. I do not fear now. B12 can only do good either for just a deficiency or pernicious anaemia. Don't worry ok. 

    Take care

  • Thank you so much for writing. I hope my issues are B12 deficiency since so far all other tests are negative! Glad you are feeling well and strong. 

  • At least it can be treated well and easily. I only go to my doctors nurse every 2 months for a intramuscular 1000 hydroxocobalamin injection, but I give myself a subcutaneous 1500 injection  of methylcobalamin weekly with small diabetic needle. And will for life.

    Take care

  • It is quite common for neurological symptoms to seem to get worse - the degree of pain etc to increase - during the early stages of B12 treatment.

    One of the effects of B12 is on the nervous system meaning that nerve cells aren't communicating so well with the brain.  When you start getting B12 it can mean that the nerve cells suddenly start communicating a lot better.  My personal theory is that it is a bit like having turned up the radio to listen to it because the reception is really bad and then suddenly the signal comes through a lot better and it is painfully loud.

    Being very susceptible to anxiety is another symptom of B12.

    B12 deficiency is generally caused by an absorption problem - could be PA (an autoimmune condition) or could be a number of other things.  Because the body is usually very good at storing and recycling B12 it can take a very long time for a full blown deficiency to develop, but once the deficiency starts to bite the symptoms tend to snowball.  Left untreated a b12 deficiency will eventually kill you.  As it is an absorption problem you will need to find another way of getting B12 in to you - generally this means injections - a number of shots over a short period to get your levels up followed by periodic top-ups - which if you are being treated with cyanocobalamin would generally be monthly - though people do vary a lot in how they retain and even how they process different forms of cobalamin once injections have started.

    Rather than being a good sign the diminishing of the symptoms you had when you started loading shots may actually be indicative that you are starting to be deficient again (at the cell level)

  • Thanks much Gambit62. Do u think 280 was low? My B12 level jumped over 1000 only 2 days after my 4 injections. Sorry but I don't understand your last paragraph. I repeat, I had mild symptoms during 2 years - until I received my 4 injections which were administered during a self inflicted anxious period. Can you please explain what "Gastric Parietal Cell Antibody, IgG" of 1.3 unit means? Does it mean my neuropathy is not due to B12 deficiency? Does it mean I do not have pernicious anemia?

    Thank you Thank you!


  • Please also remember you only have 20% of that total serum b12 that was measured. So that's not much .

  • Except that factor is taken into account.

  • a) high results after the loading mean nothing - says nothing about what is actually happening with B12 at the cell level which is where B12 counts

    B12 is not toxic and hydroxocobalamin is used in significantly higher doses than you are using (2-5000x) to treat cyanide poisoning

    b) personally I wouldn't go by symptoms were mild but have been made worse by the injections.  People can feel a lot worse before they feel better - numbness is often replaced by pain as nerve cells start to get the B12 they need to work properly.

    Have you mentioned the pain to your neurologist.

    c) I'm not an expert on tests for PA - ie IFA or PCA but I think your tests show that you have antibodies in your blood.  This could be an indicator of PA but thyroid problems can also cause positive results.  Your GP should be explaining you to what the results mean.

    d) there are a lot of causes of absorption problems - PA is one - another is low stomach acidity and there are others - whatever the cause - unless it is lack of B12 in your diet - the treatment is the same - injections and they need to be for life.

    B12 is only found in animal products so if you are a vegan or have very little meat/dairy/fish in your diet that will eventually result in a deficiency which could be corrected orally.

    However, it is possible to have no B12 in your diet but also have an absorption problem.

  • Why do you mentions cyanide poisoning? I understand cyanacobalamin injections have small doses of Cyanide, correct? Do you think that can be the cause of my increased hot symptoms after my 4 injections? Thanks much for writing.

  • He is saying that gigantic doses of hydroxocobalamin are used to treat cyanide poisoning. Something like 5 GRAMS. (In other words, two to five thousand times as much as you have been taking.) That is just to demonstrate how extraordinarily unlikely that B12 itself is ever toxic.

  • Thanks!

  • Hakimzadeh, I hope by now you are feeling much better about your PA diagnosis. There are thousands of us out here who have all gone through the process of researching what this is all about. Please ask your Dr to explain it to you again. I am continuing to discuss the topic with my GP even 18 months after my diagnosis. 

    You are very lucky to have found out about this disease. It is very important that you continue with the B12 injections - my feet still burn but I just use them as my door bell to tell me I need MORE injections, not less. 

    I am in Australia and my GP organised an endoscopy (camera down throat). It was only day surgery and it was important because it meant they could see that my stomach(ileum) was damaged because I have antibodies (fouund by blood test). So, may be a good idea to ask for the endoscopy. 

    Good luck. You are on a terrific site with lots of help available.

  • as helvella says it was an illustration of the fact that B12 is not toxic.

    shydroxocobalamin bind very tightly to the cyanide molecule and is converted to cyanocobalamin. 

  • Yes, cyanocobalamin does release cyanide when it is processed to the active forms of B12. However, the amounts involved are minute.

    You'll ingest more cyanide by drinking a quarter of a small glass of prune juice than from a 1000ug injection of cyanocobalamin.

    One cigarette releases 100ug of cyanide - 5 times as much as 1000ug of cyanocobalamin.

  • Hi hakimzadeh 

    Please don't fret about your burning feet or the safety of cyanocobalamin or even whether you actually have P.A. or not.

    It is so easily treated.

    I've been on cyanocobalamin injections every four weeks for 44 years (and I'm still "clivealive") and yes I do on occasion have burning feet and legs and some of the other symptoms in the run up to my next injection.

    If my legs are hot at night I simply fold back the duvet cover - the last thing you need to do is to worry too much about it.

    You don't say what Country you live in.

    I wish you well for the future.

  • Thanks much Clive. I don't think I have PA - so far for 2 years my diagnosis has been small fiber Peripheral neuropathy with symmetrical tingling sensations in the feet - my condition worsened (burning sensation) in March after a very stressful period which included 4 injections. I am just confused about all the different types of B12 and the absorption/mal absorption factor. Thanks again.

  • As I understand it hakimzadeh cyanocobalamin was the first form of injectable B12 which is I why I was put on it back in 1972 - and still on it today every four weeks.

    Hydroxcobalamin is said to "last longer" which is why it is given every 12 weeks in the U.K.

    Methycobalamin is yet another form of B12, said to be more "effective" than the other two but I don't think it is available as an injection on prescription from our doctors here in the U.K.

    Going back to your original post, hopefully your burning feet symptoms will ease over time and what you are feeling now is not unusual.

    Can you tell me where you live?

  • Hi Clive, Thanks much for the info. I live in NYC since 1986. Am currently in the Dominican Republic but returning home soon. I am hoping that at some point the hot/burning sensation in my feet will disappear. Also praying that the cause of my idiopathic Peripheral neuropathy has been B12 deficiency. I can deal with the pins & needles & numbness in my feet (toes and ball of feet) but the hot burning sensation at night time ain't easy to deal with :-( I can sonly sleep (a few hours)  with medication (Xanax)  for now until I will soon start taking Lyrica or a similar drug  which I guess oppresses the nerve pain. I am also planning to do start acupuncture, I hear can be very effective! I like your optimism my friend, but what do u mean by "it is so easily treated"? Goodnight.


  • Once your levels of B12 have been raised back to "normal" you will only need "maintenance" shots every month on cyanocobalamin or two to three months on Hydroxocobalamin either from your doctor or by self medication.

    It might pay you to have a look at your diet to see if you can increase your intake of  B12 as this can only be obtained naturally from red meats, fish, poultry eggs and dairy products.  Eat these with leafy green vegetables for folate (B9) and they will work hand in hand with the B12.

    Be safe on your travels - it's goodnight from here in the UK


  • Goodnight to you from Las Terrenas, Dominican Republic.


  • I also have burning feet, which may be due to B12 - I have found putting them under a cold shower, or on an ice pack, is good.  Get them really really cold! Also you can get cooling gel, used for muscle rubs, also good.  I also had Lidocaine ointment, which is a local anaesthetic to rub in, and Capsaicin cream, which is made from chilli peppers - it stops the nerves transmitting pain.  Finally, because my doctor was concerned about my using too much Lidocaine, I have found that Vagisil, available without prescription, is nearly as good and much easier to rub in.  It has 2% active ingredient whereas the Lidocaine is 5%.  I have heard that wrapping them in cling film helps too!  It's good for real burns, and if the burning you are getting is like the pain from a real burn, maybe keeping the air off them will help.  Haven't tried that one yet myself.

  • thanks much Chris. 

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