After getting B12 blood test, my doctor who wanted to reduce the frequency of injection and told me that too much of B12 could risk cancer. I am not aware of this after having read various B12 related article and I think doctor was trying to scare me off. Was my gp gave me correct information?
B12 and cancer: After getting B12 blood... - Pernicious Anaemi...
B12 and cancer
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Erainy
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You'd probably be better off asking your GP to provide you with the evidence rather than asking us to prove a negative.
It's virtually impossible.
Thanks poppet, I knew it was a fib!!
I won't challenge the doctor though...you know what they are like when they are challenged their knowledge. 
To be honest I'd simply ask him outright. It's not challenging him. I'd just say could he provide the information because you can't find any. Tell him you did find this though - and print off the abstract and responses to an article in the BMJ Online - Vitamin B12 Deficiency by Hunt 4th September 2014.
And then ask him to put the research paper with your records.
That should shut him up.
These is some research that justifies some concern, altrhough folic acid is more likely to be a problem, see:
pernicious-anaemia-society....
I have to be honest, there are always 2 sides to a coin.,increased B12 increases cell production, if you have cancer cells they will increase as well, my simple explanation...Marre.
Poppet11 in reply to
I've seen contra indicated arguments, Marre which explain quite well the theory as to why the b12 doesn't increase cancer cells. But I can't remember what they are...
It's actually quite simple, but I simply can't remember. I'm often like this of an evening....
Hi Erainy,
You're far more likely to get cancer from having too little B12! Maybe your GP was just trying to save money?
MariLiz
Like MariLiz, I thought lack of B12 made you more prone to getting cancer (of the stomach especially)
Everyone is right really. B12d can cause certain types of cancer. Marre is right in that there has been research based on the assumption that because b12 promotes cells then the implication is it will cause cancer to spread faster. But I do know I'd seen something to contradict that - and it made real sense.
They also use warped vitamins to treat certain types of cancer - and they have done that for a long time.
Interesting subject but I'd be far out of my depth if I stuck more than a toe in the water!
Would you mind expanding what 'warped vitamins' means? Never heared of it hence have faintist idea what it is. LOL
My understanding is B12 repairs damaged DNA promoting healthy cells, more chance of preventing cancer and does not cause cancer but if you have active cancer cells B12 will be attracted to cancer cells. So if having treatment for cancer B12 levels should be monitored. I belive there are studies in dogs where B12 is used to transport high doses of Nitric Oxide to Cancer cells, Cancer cells don't like Nitric Oxide (this is something I have only red in Veteranry medicine) but interesting
I would really like to know if there is any official research on the B12/cancer discussion. I am currently fighting with GP to increase my 12weekly doses. However I had cancer 17 years ago and thankfully I can still tell the tale, but you will see why it concerns me. Anyone know anything???
Can I ask what kind of cancer you had?
This is a huge subject and I am sure you can understand that we don't want to say, Yes, do this, or No, do that. If you let us know what type you had then I'm sure it will jog a few dormant braincells to recall some research we have seen somewhere...
Hi, It was cervical cancer , which I understand is caused by a virus. Interestingly following surgery and radiotherapy I developed Hypothyroidism and at that stage the GP discovered I had enlarge red platelets. He mentioned then that it could be an absorption problem and I was referred to a hematologist who was more interested in my constant cough. there was no further action. 15 years later PA was diagnosed after my failing to recover from a intestinal infection. My levels were 72! I was exhausted and suffering many neuro symptoms . I was treated in England with Hydro-something (sorry Im dyslexic) but have recently moved to Munich and my last shot was Cyanoc.... So here you have a full potted history. I always wondered if there were links and if so what the 'might' be. I certainly don't think my autoimmune system is that great!
Anything you know or links- greatly appreciated and thanks for taking the time to respond.
Okay.
I can't give you a direct link to the bit I want because my laptop overheats when I go into Youtube. But there is a section on a video Diagnosing and Treating Vitamin b12 Deficiency - it has over 130,000 hits so it isn't difficult to spot - but it is over 50 minutes long. It has a small section in there about the cellular pre-cancerous changes caused by lack of b12.
Interesting that you got worse after your op - nitrous oxide oxidises b12 - so if you have a deficiency brewing it will make it worse.
I had the pre-cancer changes back in the early 90s. I had an op. I got worse after the op both with sinus trouble and other breathing problems. Turns out I had also developed a lactose intolerance.
There are some good b12 doctors and scientists in Germany. Maybe you could contact one of the scientists and ask them to recommend a specialist?
Wolfgang Hermann is one (he's a scientist and I'm not certain if his name is actually Hermann Wolfgang!) but there are a fair few others.
I've got his email address somewhere.
I think a guy called Glockner also has done some b12 work and he is also, possibly, German.
To be honest, if you can get the right contacts, you are in the best country in the world to get the answers you need.
And the kinds of b12 you had are
Hydroxocobalamin and Cyanocobalamin. If you need them for future reference.
Hi, Ah thanks that was very helpful. And yes I was told if I didn't get sorted in Germany is would never be sorted. i will look up the names you have given me. If you have email address that would be great. Next time I go to my doctor here I will ask him more about specialists and various referrals. It seems much easier to get a referral here than in GB. mmmm Intolerances , interesting, I definitely developed an egg intolerance and am now questioning a lactose intolerance, too many links to be a coincidence?
Again many thanks for your responses.
Be well
this is an old thread but i was just searching this forum. doityourself here are two studies (google the titles)
Cancer Incidence and Mortality After Treatment With Folic Acid and Vitamin B12
Effects of Lowering Homocysteine Levels With B Vitamins on Cardiovascular Disease, Cancer, and Cause-Specific Mortality
one shows a link with b12/folate, the other contraindicates (the latter was a larger sample but over less time)
no-one knows if it is b12 or folic that is the culprit (if there is one). but i think b12 allows the body to produce more folic acid anyway...
I don't know much about this either but from what I've read some cancer patients have been found to have elevated B12 blood serum levels but it is not known whether the high B12 level has caused the cancer or whether the B12 level is high because of the cancer for some reason that we don't yet understand.
Gambit62Administrator
My understanding of studies that I have seen is that there is a co-relation between treatment for B12 deficiency and cancer, ie higher proportion of people being treated for B12 develop show up with some types of cancer ... a co-relation is very different from a causal relationship and I am not aware of any study that has shown a causal relationship. In fact it is quite possible that cancer was a consequence of the original B12 deficiency so the co-relation is a manifestation of the impact of low levels of B12 (and B9) in leading to cancer rather than being because of the treatment.
Been trying to think of a reasonable example of the difference between correlation and causal link so here goes ...
It's well established that people living near and in the arctic circle have higher rates of suicide. Most Swedish speakers live in Sweden which is near and in the arctic circle so I'd expect to see a higher than average rate of suicides amongst Swedish speakers ... that's a correlation but not a causal link. Speaking Swedish doesn't put you at higher risk of committing suicide ... just in case anyone is learning Swedish and was worrying about the possibility 
If I wanted to do my head in learning another language I'd choose Norwegian - but thanks for the suggestion!
A page that might be of interest
canceractive.com/cancer-act...
This statement might be of particular interest:
"No doctor in his right mind would try to persuade you not to consume or supplement vitamin B-12if there were signs of deficiency..."
However I'm going to qualify it - I believe (and could go look but I'm feeling too lazy) that there was a situation way back where it was shown that folate made the kids with leukemia die faster.
Obviously we are aware that b12 deficiency can result in a higher incidence of some cancers - but I know you need to know that it won't make a possible cancer worse.
I still think we need to know what type of cancer you had to focus the search more effectively.
Wow! Look at this postscript:
"Interestingly, this standard EU-approved vitamin supplement (cyanocobalmin) has a formula barely different to that of ´rogue´ synthetic vitamin B-17, the controversial, and banned, vitamin that reacts with an enzyme called glucosidase, uniquely found in cancer cells, releasing its cyanide component. Both synthetic supplements have similar ´cyanide´ components. While doctors protest about B-17, they wouldn´t dare to criticise their own use of B-12."
Wow! Double WOW!!!!
(I've reverted to being 14!)
I don't understand that postscript!
The overall formula of the two substances is huge.
B12 = C63H88CoN14O14P as against so-called B-17 = C20H27NO11
The cyanide aspect is also hugely different in terms of amount. From what I can gather (very quick search) B-17 is used in multiple-milligram amounts - e.g. 500 mg tablets - whereas B12 only just gets into the very low milligram amounts.
So whereas with cyanocobalamin, at least in fairly ordinary doses, the amount of cyanide might fall within our ability to cope, that associated with B-17 appears to be way above that.
Mind, I take methylcobalamin as my preferred form. (Not PA - just get slight but good effects.)
In looking this up, I fell across this,which I had not realised:
Historically, a form of vitamin B12 called hydroxocobalamin is often produced by bacteria, and was then changed to cyanocobalamin in the process of being purified in activated charcoal columns after being separated from the bacterial cultures. This change was not immediately realized when vitamin B12 was first being extracted for characterization. Cyanide is naturally present in activated charcoal, and hydroxocobalamin, which has great affinity for cyanide, picks it up, and is changed to cyanocobalamin.
en.wikipedia.org/wiki/Cyano...
Which also make me wonder what the impact is of eating charcoal biscuits, taking charcoal capsules, etc. And how many other substances are contaminated by cyanide from activated charcoal (whether things we consume or substances being analysed in laboratories).
Rod
I know that original when Dorothy Hodgin Burnett - I think - was analysing the chemical structure it was originally thought that all b12 had the cyanide molecule - they then believed cyanocobalamin was the most 'natural' form. I think that myth has prevailed to this day in the minds of many as well. But then it was realised that the cyanide molecule was picked up, as you rightly point out, in the processesing. For years though cyanocobalamin was the only b12 available because they could not make the hydroxo stable.
I believe (and I'm no scientist!) that with cyano the molecule it actually replaces is that of adenosyl. Pretty important even if you take the cyanide situation out of the equation!
I've taken cyano both in tablet and injectible form. The tablet form was in low dosage at the very commencement of my treatment and within 2 days my symptoms (particularly relating to eyes) were back with a vengence. Whether it was the low dose or the cyano I could not say.
With the injectible my symptoms come back, but I have only tried it after years of methyl treatment. I can't say it does a thing for me.
One problem I have with the cyanide in cyano is in the injectible form. We can't compare (I don't think) absorbtion of cyanide from food stuffs and the effects of absorbtion from injecting straight into the body.
Also just to add, since we were talking about cancer - I wonder if the problems relating to research such as Marre mentioned were undertaken relative to treating b12 deficiency with cyano? I know you have pointed out the difference in values - but would small amounts still have a detrimental effect in such situations?
But I am certainly no scientist, it just strikes me that it's like trying to compare milk and diamonds.
I don't think you're correct in saying that the cyanide molecule replaces an adenosyl molecule but I'm struggling (so far) to find anything to confirm that. I believe it replaces some form of methyl donor but I'm not sure what. Are there any proper scientists/biologists on here?
It's in Kevin Byrne's paper on the enterohepatic circulation.
I've got it here somewhere...
Here you go. It's in pages 2 and 3.
b12deficiency.info/assets/t...
I've spent too long on the internet looking at this and my brain has gone numb. From what I've read, a methyl donor is required to remove the cyanide molecule from cyanocobalamin but the methyl donor isn't necessarily adenosyl although it can be. Anyway, I've had enough and it's moot for me as I have no intention of using cyano.
I just want to understand it - but I get brain numb too!
I was laughing when I posted the link - actually it was more a witch's cackle. Read and inwardly digest. Or not, as the case may be!
Poppet, Thank you for digging the info. tbh, your postscript flew over my head 
and I need to read it again tomorrow when my brain is a little more fresh. LOL
I don't think B17 is bad.
I know were are diverging to another vitamin but people who eat bitter apricot kernels (certain tribes I think) has no cancer.
But, of course, anything that prevents cancer would be outrisized e.g. vitamins and EU (directive) has been busy banning the availability of high dosage vitamins. You see vitamins are good but not profitable for pharma industry if everyone got the right information and become healthy.
Here is a book about B17.
in reply to engels
My understanding is that cyano cobalamin needs further converting in body; the cyanide molecul is taking off to become hydroxo to then be metabolised into methyl and adeno cobalamin if all works well in your body. An other positive "side effect" of using hydroxocobalamin is that it clears out cyanide in the body, as hydroxocobalamin attaches to cyanide to become cyanocobalamin. so its used for cyanide poisioning in smoke inhalation etc, but the above is what I've read and have been told, if its true I do not know, I'd not want to put lots of money on it.
There was research that implied the cyanide in cyanocobalamin was harmfull to cancer cells say (so not hydroxo B12), but think that is not accepted as treatment say see:
Info about cyanide:
inchem.org/documents/pims/c...
Cyanide can be of natural or synthetic origin.
Natural origin: cyanide is found in foodstuffs such as
cassava, cabbage, spinach, mustard and in the kernels of
apples, stones of peaches and plums, as well as in cherry
stones and in almonds. Another source of human exposure is
tobacco smoke.
Laetrile (amygdaline or vitamin B l7) was used as an anti-cancer drug:
Laetrile, amygdalin derived from apricot kernels, has been
used as an anticancer agent, but is now obsolete because a
therapeutic effect could not be demonstrated in either
retrospective or prospective studies; laetrile has caused
fatal cyanide poisoning (Braico et a1., 1979).
Carcinogenicity
There is no evidence of any carcinogenic effect.
Indeed, in the past there was a vogue for using cyanide
(amygdalin, laetrile) as an anticancer agent but this use is
now obsolete.
Adults
7.2.5 Acceptable Daily Intake (ADI) and Other Guideline
Levels
The Food and Agriculture Organization and World
Health Organization have recommended an ADI of O.O5 mg
cyanide/kg. The life-time Acceptable Daily Intake for
an adult (Drinking Water standard) is 1.5 mg/day
(equivalent to O.O2 mg/kg/day), based on a 7O kg adult
(EPA, l986).
Oh well its all so very delicate and in the end we are just the blind leading the blind!
Kind regards,
Marre.
Poppet11 in reply to
Have you got any further links, Marre.
I'm stuck on the bit about the cyanide molecule converting into methyl and adeno.
The cyanide molecule is an accident of processing - or at least it was originally. I just can't understand how it can convert into anything - although I understand it breaks off.
in reply to Poppet11
No the body takes off the cyanide molecule first, Cyanocobalamin needs more converting than hydroxocobalamin as it first needs to take off the cyanide molecule, I'll try to find a link, but its taken me over an hour already to find the above link , need a rest (coffee) now!
Poppet11 in reply to
Now you've explained the bit about the cyanide molecule I'm reading it differently.
in reply to Poppet11
OK good I'm goggle eyed and shutting down, having read so much that just diverted me to other things to then not know what I was looking for!
Poppet11 in reply to
I'm still confused over all this - probably because the basic Wiki stuff seems to contradict the Kevin stuff from the outset.
The Kevin stuff says that the adeno ligand is replaced by the cyanide molecule. The Wiki stuff says the cyanide molecule is replaced by adeno or hydroxo or methyl.
I know I have a 'picky' little brain but I like to get my footing right at the outset or it sends me all wrong.
It could be of course that the adeno is replaced by the cyanide and then later the cyanide is replaced by another cobalamin.
The cyanide is removed from the cyano thereby converting it back to hydroxo but we know that hydroxo has a strong affinity for cyanide so what prevents it from grabbing the cyanide back again?
But in the earlier stage the cyanide replaces the adeno, yes? This being necessary to make the cyano stable.
... and I get what you mean about grabbing the cyanide back.
But then again won't that be the hydroxo which is flushed from the system? Stupid question because we simply aren't scientists.
Mind you, scientists have been getting the b12 issue back to front for decades so what the Hell do they know!
But the starting point for producing cyano is hydroxo. Cyano is simply hydroxo which has been filtered through charcoal in which process it picks up the cyanide. Take away the cyanide and it reverts to hydroxo.
As I understand it, when hydroxo is used to counteract cyanide poisoning the hydroxo grabs all the cyanide thereby converting itself to cyano which is then excreted in the urine as is usual when the body has more B12 than it can cope with.
Why do all these things lead to more questions!!!!
Okay, I'm not contesting what you say but it would seem to be different to what is in Kevin Byrne's paper?
Next problem - why turn perfectly good hydroxo into cyano so the body can convert it back to hydroxo?
Yet cyano is cheaper to produce than hydroxo...
See what I mean?
If we catch a scientist I vote we chain him to a chair and do whatever is necessary to make him talk!
in reply to Poppet11
What I wrote is what I was told by a Dr at a PAS conference, its the nearest I got to a scientist. I think you have to get passed the fact that first the cyanide molekul is detracted from cyanocobalamin, then starts the convertion/ methylation into the 2 active forms for which a lot more is needed, but it just does not include the cyanide molecule I think. But any free hydroxo (not methylated, and or taken up in what ever cycle) will attach itself to cyanide before it is taken up say to then be flushed out by kidneys as cyanocobalamin. It is only my simple thinking. There are so many more enzymes and weird other processes that take place, way beyond me!
Poppet11 in reply to
It's not a case of getting past it, Marre. It's a case of understanding what happens and why?
You know as well as I do that many, many professionals have been getting the whole b12 thing wrong for many, many years - that's why I need to understand for myself. I think most of the stuff they have done needs challenging and we can't challenge it, until we understand it.
My main problem at the moent is understanding the differing cobalamins affecting the different metabolic pathways - because that means we 'might' have been going a little wrong ourselves. But to understand that I have to understand what each 'cobalamin' does...
I'm a difficult little person (or so I am told!)
Don't get confused with price!! Less is more. lol
It's like more crap the vegetables are sprayed with, it's cheaper but organic produce contains less chemicals and cost more.
Oh, I use methyl - I just want to know the biochemical effects.
Cyano doesn't work on me - at all - so I don't use it.
You've got your synthetic cobalamins and your animal irrelevant cobalamins and your animal relevant cobalamins.
I'm just trying to sort the wheat from the chaff and want to work out how each works and in which metabolic pathway. Although the animal irrelevant cobalamins are just the analogues.
Personal experience trumps theory!
Rod
Yeah, but, has it been peer reviewed...
Then again, as I understand it, cyano converts to hydroxo - and since no one seems to understand what hydroxo actually is, it all leads to me getting one helluva (nearly an anagram of your ID) headache!
So had all the other papers which were later withdrawn (across the whole of the scientific/peer-reviewed arena, not only medicine).
As I understand, hydroxo is simply a hydroxyl group (oxygen plus hydrogen - OH) when a part of a molecule. So conversion of cyano-C to hydroxo-C whips off a CN and replaces it with an OH. Converting to methyl-C whips off the OH and bungs on a methyl group.
Have fun making some more anagrams!
Rod
Yes and no if you had cancer it would grow fast with the b12 alot of cancer meds starve the tumor by block the avaibility of b12 and folate
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