PA here and Hydroxocobalamin every 7 weeks, keeping me out of symptoms and on my blood test usually around 600-800 nmol before my next jab at the Drs.
The other day my Dr said that he had seen studies that showed an elevated cancer risk when supplementing with B12 and having levels above 800 nmol...I seem to recall a pub.med article about this, but I cannot find it. Is he right, should be more like 500-600 before the next jab?
Does anyone know of the studies?
FYI I had breast cancer in 2015 and have recovered well (in 2012 I had several Iron infusions in the hospital over a period of time before my PA was discovered - maybe that had something to do with a cancer 3 years later...Who knows...
Written by
indywindy
To view profiles and participate in discussions please or .
Here are two studies I found. The first concludes that:
"Solid cancers represent one of the main diagnoses found in patients with unexplained and persistent elevated B12. "
But the key emphasis on this report is 'unexplained' elevated levels. In the case of PA and B12 supplementation, we have an explanation. There's an intended elevation.
"Some authors suggested that the development of solid cancers could be secondary to the elevated B1227,28. Indeed, vitamin B12 is the cofactor of methionine synthase, which is implicated in methylation reaction and in the synthesis of purine bases29,30, and these functions are crucial in tumor-initiating cells and cell proliferation30,31. On the contrary, we think that certain cancers would be, directly or indirectly, responsible for B12 elevation. Moreover, Arendt et al. showed that the SIR of cancers was higher within the year following B12 measurement than in subsequent years16. This supports the presence of undiagnosed subclinical cancer rather than a hypothetical role of the elevated B12 in the development of cancer."
So it is saying that any tumours could cause elevated b12 levels.
And if it's any consolation, all my health troubles start at roughly the same point. It began with a benign parotid gland tumour and suspected bowel cancer, for which a colonoscopy removed three polyps. Then they found a thyroid nodule before missing B12 until I lost control of most of my mental and physical functions.
So, the tumours, which were thankfully benign, potentialy began because of lowered b12.
You could use this evidence to suggest to your Doctor that any cancer would be the CAUSE not the EFFECT of high B12.
Thank yoy so much for thos elaboration and opposite perspective and hypothesis as to the possible connection. And like the authors say..., it is quite possible that a cancer in itself could elevate the B12. I don't know whether this is the actual study he was referring to, but I will send it to him. I cannot from the study see any exact numbers/referencer to which degree they are considering it elevated. He said specifically 800 nmol.
Hope this is the one, and that he could be misinterpreting it.
Do you know of there are others regarding this connection?
My pleasure. I'm not a doctor, but I do know that there are no proven cases of overdose of B12.
Plus, both these reports together suggest elevated B12 levels is cause for concern. However, that's not the same as elevating you're own B12 levels and getting the same reaction (i.e. tumourous growths).
I think it's a fine balance. If you run out of B12, your body needs it to repair. And to date there are no figures of where the B12 should be, since ranges are different across the country and the world. I.e. there is no given level to suggest someone is 'deficient'. You could live in Wales and be very deficient, or Sheffield and be told you're in range or 'normal'. So, if there is no assumed deficiency 'level' how could there be an upper or optimal level? There is no such thing.
So perhaps the Doctor could, by return, provide evidence of where he gets 800nmol aa the optimal level. I would say that is a fair exchange !
And thank you for your kind wishes - when it rains it pours! Thankfully on the mend
My understanding has always been that this connection is not in patients that are supplementing, so GP needs to check more thoroughly before scaremongering.
My problems, as far as I'm aware, began in 2012 with salivary gland infection due to saliva duct strictures. I was later given a procedure to relieve the swelling and pressure.
It was in 2015 that I went to the GP with fatigue, diarrhoea and lower back/ l/h groin pain.
I was sent for a colonoscopy as there was the possibility of bowel cancer. Two small benign polyps were removed, but were not the cause of the problems, which continued.
B12 deficiency was found early 2016.
I have had problems reducing or eliminating B12 deficiency symptoms on any of the frequencies offered to me - and have resorted to self-injection to attempt to do so. It has been slow work and recovery not always a stable upward trajectory. However, I am now much better than I was.
I was told by a senior ENT consultant in a major hospital, back in 2017, that I was doing the right thing with frequent B12 injections, to continue to do so, and not to give up as it would take a long time to get well. He also said that there was a link between compromised saliva flow and subsequent b12 deficiency because I asked him whether a lack or reduction of salivary haptocorrin would mean less/no protection of B12 etracted from food.
He is a rare gem - and his advice kept me on track at a very difficult time.
So it is possible to have an extrinsic factor malfunction - a problem right at the start of the process rather than further along - intrinsic factor lack / under attack from antibodies (PA).
- Or in addition to !
Is it also possible that a benign parotid gland tumour, or the surgery to remove it, could have caused you similar problems initially - or at least contributed ?
I am really sorry that your B12 deficiency remained undiscovered for so long. Glad that you are now healing and that tumours were found to be benign.
indywindy -
My initial B12 level was not particularly dramatic (196 ng/L with range starting at 197ng/L ) so I was lucky there. Four months after treatment started, it was over measurable amount, due to injections given (over 2000ng/L). This was taken on the same day as an injection was given. Two months later, before my next 3-monthly injection was due, my level was 860 ng/L, still over the top of the range. Yet by then I was unable to work or function properly.
Two months after that, the GP started B12 injections at two per week and had my serum MMA (methylmalonic acid) tested, suspecting a functional problem. It was raised. It should have linked with the injected B12 and moved on to cell/tissue. Having raised MMA, despite the usual loading dose and maintenance dose, gave me a diagnosis of functional B12 deficiency, confirmed by the hospital laboratory because my GP had already had renal problems ruled out. Later I had a small intestine bacterial overgrowth (SIBO) breath test to rule that out too.
In spite of frequent B12 injections, my MMA remained raised for about three years but on the 6th test was finally mid-range. My ferritin and folate took about two years to stabilise with supplements and my osteoporosis of the spine has recently been reduced to osteopenia with vitamin D treatment and Raloxifene - and a lot of walking.
All of this needs close monitoring - my folate and ferritin have dropped a bit too much lately - except my B12 as this will always be over 2000 ng/L.
It is the only way I know of to prevent deteriorating again.
For those with B12/MMA problems at cell/tissue level that are able to be identified in DNA, the medical advice to GPs is to administer B12 at two injections a week for life. Unfortunately the Inherited Metabolic Diseases consultants were unable to locate the problem with me, but this frequency seems to work for me anyway.
I am not a medical professional, but thought it worth mentioning that there are those who are treated with long-term frequent injections by the NHS, because otherwise they could not survive.
Thank you for your lovely and interesting reply Cherylclaire. It's very helpful to hear that someone else had similar challenges that may or may not have applied to B12D. I never even thought about extrinsic factor - that is very interesting indeed.
I am glad you found a helpful professional to give you the right advice. I'm also 'keeping going' in a similar way.
Yes, I did go to the GP in March 2020 but they attributed it to stress. And the problem was, I had been very stressed. I'd moved house and lost my job in the same year, plus bowel problems. And there is a family history of that.
Then when the pandemic happened I moved my focus to the surgery for the Parotid Gland. And so I that happened in Aug 2020 when they also took half my thyroid. And most certainly I was under deep anaesthetic - if it was nitrous oxide I don't know. If it was then that most likely didn't help me at all regarding B12.
Don't anaesthetists check vitamin levels pre-op, if they know nitrous oxide could deplete B12?
It's all very interesting to ponder whether a deficiency could cause so many malfunctions. And Doctors never raise the question about vitamins - it's just assumed that you eat well and that's that. But then there is also the role of stress on the body, toxin accumulation and problems with absorption.
It's so complex, I think. But I do suspect medics are missing a vital trick by not understanding more about B12.
I have made it clear on occasion to anaesthetists/ dentists about nitrous oxide just in case. On the subject of dentists, I have met dentists and opticians who seemed to be more aware of B12 deficiency. Good to have an optician who checks for potential damage. You only see what you know to look for - unless you are as poor-sighted as myself, and no-one would want that in their optician !
Hope you find some answers and hope you'll update the thread if you do.
"my Dr said that he had seen studies that showed an elevated cancer risk when supplementing with B12"
Have you asked him for the titles of the studies so you can check for yourself?
I do wonder if your dr might have read articles that state high levels of B12 have been found in some patients with cancer and interpreted this as meaning that high levels of B12 can cause cancer.
I'd also suggest looking at how many patients were in studies. I'm not a scientist but I think that the larger the sample size the better.
Thanks so much for the links - I will look into them.In Denmark there is a very strict and rigid understanding of the guidelines of max 500 nmol, and not a particular look at symptoms. They only consider below 200 nmol too low. Usually a jab every 3 months.
At the beginning I had to fight for my right to get rid of symptoms. Now it is not a problem, but it took some effort.
Think it is important to understand the terminology used in research literature'greater risk' = there is a positive correlation in results. It says nothing about whether there is a causal link.
To illustrate - there is a higher risk of having a large shoe size if you are taller - but that isn't a causal relationship - it is a correlation.
Being B12 deficient puts you at higher risk of cancer.
Elevated B12 (in patients who haven't supplemented or received injections) can be an indicator of liver and kidney problems, which would include cancers. the causal mechanism leading to elevated B12 is the liver dumping stores of B12 or the kidneys not functioning properly in removing excess B12 so levels build up.
Elevated B12 levels are associated with higher risks of B12 and larger tumours - no causal mechanism for the higher rates of cancer has been identified. The larger tumours may well be the result of B12 promoting the reproduction of cancerous cells, as it does with healthy cells.
On B12 levels - your GP - like most GPs seems to be under the impression that people respond to injections in the same way - the studies that are used to justify the average of 2 months for hydroxocobolamin showed a huge variation in how quickly B12 was removed - with some patients actually retaining high serum B12 levels for years - so although 2 months is an average that doesn't mean that everyone will clear B12 in 2 months. Unfortunately the studies only recorded levels they didn't reflect reported symptoms.
Thanks so much for the elaboration, also on the liver and kidney cancer context - and interesting with the induvidual clearing of B12. ....Thinking then that my 600-800 nmol level every 7 weeks will be alright then. Will have to find and show these studies, for it seems that there aren't any studies showing a specific causal cancer effect on a slightly elevated and yes, constant B12 level - to your, nerded knowledge(👌).
I am not sure that I can get him to find the time of finding the studies he was referring to - too busy, and to uninterested in the matter, just saying, you know...
Thanks a lot for your reply.I was also under this impression from previous studying it, regarding the relatively higher level being a better and safe haven contrary to the opposite level and deficiency!
But the Dr was saying that maybe I should go longer between my jabs, than the 7 weeks...I am quite content with him though, he is private and an orthomolekylær Dr with Vit C injections etc (and who was looking over my values and history)
"Dr was saying that maybe I should go longer between my jabs, than the 7 weeks."
Have you thought about keeping a daily symptoms diary which tracks changes in symptoms over time and when any treatment is received. You could also note any relevant blood test results.
Keeping a symptoms diary can be useful evidence of deterioration or improvement in symptoms to show the doctor.
For example if your symptoms usually deteriorate before you get the next injection, that suggests to me (I'm not medically trained or a scientist) that you probably need more frequent injections.
If over a longer period of time, symptoms are slowly deteriorating or new symptoms are appearing, that suggests to me that maybe more frequent injections are needed.
If you do decide to try spacing out your injections, I think it makes sense to do it very slowly eg by a day or so and then track how your body responds.
As far as I know from scientific research articles I've read, having pernicious anaemia increases your risk of getting stomach cancer, and not the B12 injections themselves. The article below mentions this briefly: cancer.org/cancer/stomach-c...
That's right - the lower stomach acidity levels associated with PA lead to high gastrin levels which increases the risk of developing NETS - precancerous cells - which can then develop into cancer. Some people who have PA have managed to persuade their GP to arrange monitoring for NETS
I have suffered from too low stomach acid for years, so that could be the culprit of my final loss of IF that eventually resulted in my symptoms of B12 and Iron deficiency. Therefore I have been taking HCL plus betaine and Pancreatic enzymes for digestion of the food, particularly meat.Hoping to avoid gastrisk in this way.
As I was researching my own question on “can one overdose on Vitamin B12?” I did find that the question of increased cancer risk came up and I found the answer to be inconclusive. I do believe I read a study by Harvard Health that suggested that very thing.
Below are several studies, two finding no connection of B12 supplementation and increased cancer risk. One finding support hypothetically and increased risk of lung cancer, and one finding that increased serum B12 levels are caused by cancer by degrading the metabolism of B12 thus leaving higher levels in blood serum.
This study finds that elevated serum B12 levels are caused by cancer rather than the cause of cancer. In other words, the cancer is negatively affecting B12 metabolism and thus causing higher serum levels.
Elevated Vitamin B12 Levels and Cancer Risk in UK Primary Care: A THIN Database Cohort Study
Here are a couple of studies that find that Vitamin B supplementation has no significant effect on cancer incidence other than is has shown to decrease risk of skin melanoma.
Effect of vitamin B supplementation on cancer incidence, death due to cancer, and total mortality
Effect of vitamin B supplementation on cancer incidence, death due to cancer, and total mortality: A PRISMA-compliant cumulative meta-analysis of randomized controlled trials.
Maybe it's the lung cancer risk - study he is regering to, maybe not. I'll have to ask him. But like I said previously, he may not find the time. He had just concluded, that supplementing B12 was no longer limitless because of the allegedly elevated risk. But...I see that it is undoubtably questionable or inconclusive, which...isn't very nice either.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
B12 and acne risk
B12 and cancer
Increased cancer risk?
Self injecting - what are the risks
Reaction to B12 injection?
