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B12 supplements increase cancer risk in men

Wonkmonk

Senior Member
Messages
1,006
Location
Germany
I had heard about this before, but what was actually shocking for me is that the risk is increase already with rather low intakes of 55 micrograms a day orally (over several years).

https://www.theatlantic.com/health/...d20aa_ta&utm_medium=social&utm_source=twitter

55 micrograms orally means that about 4-5 micrograms are actually absorbed. Absorption is very low above 2.5 micrograms which are absorbed via intrinsic factor. Above that, only 1-3% is absorbed via passive diffusion.

When I now think that many (including me) are taking regular injections of 1000 micrograms and more, that makes me worried. Of an injection, bioavailability is 30-70% (depending on the kind of B12 - cyano/hydroxo/methyl/adenosylcobalamin - and method of injection, i.e. intramuscular vs subcutaneous vs intravenous).

So that may be 100 times the dose that already doubled lung cancer risk

I'm of course not telling anyone to stop B12, especially if it helps. But I think being aware of this potential risk is important.
 

Carl

Senior Member
Messages
362
Location
United Kingdom
The quote is taken from the wikipedia history/edits/modifications. I originally saw this on the Vitamin B12 wikipedia page but someone later removed it. I used this taking very high doses orally and it did stop autoimmune reactions to foods. It did help in other ways too. I have since substantially lowered my B12 intake.
High-dose administration of Vitamin B12 has been additionally validated to stimulate the activity of the body's TH1 suppressor T-Cells, which then down-regulates the over-production of the allergen antibody IgE in allergic individuals.

The action promoting T suppressor cell activity could be part of the reason for the increased cancer risk.
 

bombsh3ll

Senior Member
Messages
287
This certainly isn't a randomized trial and you have to consider the characteristics of the people taking the B12 and reasons for taking it. For example, B vitamins are often prescribed to alcoholics (among whom smokers are over-represented, looking particularly at the lung cancer comment), and people with pernicious anaemia (an autoimmune disease) or on long term acid suppressing medication, who cannot absorb dietary B12 properly. These groups may have risk factors for disease that don't apply to other populations. People self-supplementing are often doing so because they already have some kind of symptom or health concern, or know that they eat a limited diet for example. I would say that association in this case certainly doesn't mean causation.
 

Wonkmonk

Senior Member
Messages
1,006
Location
Germany
It' always difficult to prove causation in such studies, but I find it interesting that via the normal oral route and with a normal diet the body does only allow a few micrograms a day to pass into the blood stream of this essential vitamin, despite its ability to store thousands of micrograms in the liver.

I always thought there must be a reason for this, and maybe it has a hidden downside of taking much higher doses, espiecally if they are being injected and therefore reach up to a hundred times higher amounts than with oral administration.
 

Wayne

Senior Member
Messages
4,300
Location
Ashland, Oregon
I only briefly glanced at the article, but my initial take was that it was biased. Perhaps it's my own bias, but I've noticed our mainstream media seems to always be quick to discount various kinds of nutritional compounds, while extolling the latest in modern medicine, which seems to have a major aversion to nutritional compounds. The author in this article quotes the NIH:

But as the National Institutes of Health notes, “Vitamin B12 supplementation appears to have no beneficial effect on performance in the absence of a nutritional deficit.”​

Well, how exactly do they know whether someone has a nutritional deficit or not? I recently ran across AN ACCOUNT of a guy who discovered that B!2 improved his tinnitus, even though he tested in the normal range (albeit at the low end). Check out the first 1-2 minutes of THIS VIDEO, an account of a doctor who had become demented, blind, deaf, in a diaper, and was going to die. After supplementing with B12, he's now back in practice, though partially disabled from the extensive neurological damage.
 

alicec

Senior Member
Messages
1,572
Location
Australia
the body does only allow a few micrograms a day to pass into the blood stream of this essential vitamin, despite its ability to store thousands of micrograms in the liver.

That's not quite right.

You say that the body limits uptake of B12 when in fact it is set up to efficiently take up and reuse every skerrick it encounters. Very little is wasted - ie excreted.

This is because cobalamin is a very rare substance. The capacity of the intrinsic factor system to absorb it from dietary sources is more than adequate to take up all it is offered and it is backed by a very efficient salvage system.

Only about 1/5 of the circulating cobalamin is in a form suitable for uptake into cells and use as B12 cofactors - ie the portion bound to TCN2. The remainder circulates bound to TCN1 (aka haptocorrin). A portion of this is taken up by the liver and excreted via bile to the small intestine where it is subjected to the same processes as ingested cobalamin.

Cobalamin is extracted from the haptocorrin and sent for another circulatory pass to allow it to be taken up into cells. This endless enterohepatic loop ensures that the body efficiently uses all the cobalamin available to it.

It is this enterohepatic loop that is meant when people talk about the capacity to store B12 in the liver - there is no actual repository of B12 that is drawn on if intake is low.

Provided the loop has been well charged with cobalamin to start with (ie from an adequate non-vegan diet), cobalamin can indeed be supplied to the body for many years in the complete absence of dietary intake, until the loop suddenly collapses because one element of it no longer works (eg IF for PA patients) or cobalamin is completely exhausted (long term vegans).

Once the loop has collapsed it can be very difficult to reconstitute and even vegans, who don't have a defective mechanism but are just essentially starved of B12, may need long term high dose supplementation.

High dose supplementation relies on the capacity of cobalamin to passively diffuse across cell membranes; the higher the dose the greater the concentration gradient and the more that enters cells.

This route can be absolutely critical to provide sufficient cobalamin for many people, including those whose enterohepatic loop has collapsed for a variety of reasons and those with problems with intracellular processing of cobalamin.

The latter group may well include many people with ME/CFS since the folate system seems to be one of the metabolic pathways commonly deranged by the disease.

So yes, healthy people eating a non-vegan diet probably need no or minimal supplementation, but we are not healthy and many of us benefit greatly from B12 supplementation beyond the capacity of the IF system.

As for the so-called cancer risk, well I don't have the energy to read the original study. In general most of these scare stories about supplements are based on poorly designed studies which seem to set out to prove that we don't need supplements - so I don't have much inducement to spend time on it.
 

RWP (Rest without Peace)

Senior Member
Messages
209
@Wonkmonk

When I read your post, I did some research on this. I will fill in with LINKS later (with the appropriate url or citation). Tonight, I'm just trying to get the info down.

While I agree that this author (MD) slanted his article in an anti-supplement direction, the actual science is not as prejudiced as it might seem. And this is coming from me (and my wife's cancer doctor), both of whom are very pro-supplement in general.

So, even though those of us on PR use high doses of B vitamins for methylation, there is a concern for the general population, and even (to a lesser degree) for us.

Here is some info:

First, it is difficult to discuss the studies cited in the article because there is insufficient information about the FORMS of B12 and folic acid used (in the Norway trial). I know I could look them up, but it's not totally necessary. Obviously, as far as I know (feel free to jump in here, you methylation experts), giving "folic acid" doesn't seem like the right form---toxic? Also, in the Washington State study, the forms of B6 and B12 were not specified.

Secondly, my wife had ovarian cancer in 1995. Her cancer doctor wrote 4 cancer books during the course of her practice. In her 1999 book, she mentions that B12 supplementation causes the egg stage of Ascaris lumbricoides (roundworm) to hatch. Hence, she always made sure to treat this parasite before giving the B12 to address the uniform deficiency she found in all her cancer patients of this B vitamin, as well as folic acid (alas, perhaps, the wrong form). However, by the end of her career, she no longer mentions B12 in her last 2 cancer books, so I must conclude that she found that the proper way to address this deficiency was different than administration of the vitamin itself.

Thirdly, the reason why this is relevant is that Ascaris is a well-known, common parasite found in pets, and its target is organ . . . is the lung! That could well explain why the risk among lung cancer patients was highest (assuming I read the article correctly). By the way, Dr. Clark found Ascaris to be oncogenic (tumor-promoting) and common in all allergy and asthma patients (no surprise there).

So I'm going to end with my conclusions about how we, as ME patients should view this.

1. While not exclusively, ME patients should try as much as possible to get SOME B12 from food. I don't have the full list of B12 foods, but most of us know those.
2. Make every effort to improve your digestion and bowel function so that your Lactobacillus can produce as much as your own B12 as possible.
3. Obviously, make sure to take the proper forms of B vitamins and be aware of the risk, especially long-term.

RWP + PWR
 

Wonkmonk

Senior Member
Messages
1,006
Location
Germany
Thanks, PWR/RWP, the Ascaris is interesting, so maybe these studies would have to control for Ascaris infection (or at least pet ownership as a proxy) among their population, which they probably didn't.

A short comment to this:

1. While not exclusively, ME patients should try as much as possible to get SOME B12 from food. I don't have the full list of B12 foods, but most of us know those.
2. Make every effort to improve your digestion and bowel function so that your Lactobacillus can produce as much as your own B12 as possible.

The list of foods is very short: All sorts of meat, all sorts of fish and seafood, all dairy products, eggs. Sandthorn in traces plus some is produced by the gut microbiota, e.g. lactobacillus and possibly others), but the exact amount is unknown.

The thing is, from foods, your body will never absorb more than it can absorb by using intrinsic factor as a mechanism, and that is just a few micrograms a day. Intrinsic factor can transport just a few micrograms per meal and these foods only contain a few micrograms per serving. And a healthy person doesn't need more than that. The recommended intake is just 2.4 micrograms a day.

Tables 1 and 2 here provide a very good overview

https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/

If for whatever reason you are having a deficiency despite adequate dietary intake, you can only correct it by using injections or very high oral doses (1-3% is always absorbed by passive diffusion independent of intrinsic factor).
 

RWP (Rest without Peace)

Senior Member
Messages
209
@Wonkmonk

Good points. I have some more ideas that I will share later.

Again, I didn't discourage B12 usage (or any B vits), only indiscriminate, long-term use with the wrong mindset. I have recently taken massive doses of B vits (12 caps/day of Thorne Basic B complex, which amounts to 4-5 mg. B12) for a defined period of time, but it was in the appropriate order after other therapies (I will explain later) and with the realization that there's more to the problem than just supplementation.

RWP
 

Hip

Senior Member
Messages
17,824
The study found that out of 3416 patients taking oral folic acid 800 mcg + vitamin B12 400 mcg daily, 4% died of cancer. Whereas in the placebo group, only 2.9% died of cancer.

So that's 38 extra deaths in this group of 3416 patients as a result of the vitamin protocol.


The patients were following this vitamin protocol for 7 years, and the study continued to observe these patients for another 2 years after the protocol ended. The increase in cancer incidence in the vitamin group was mainly caused by lung cancer.

Another group of patients taking vitamin B6 alone did not show any increase in cancer incidence.

So either B12 or folate was causing these lung cancers (or both in combination).



I'd be inclined to look at folate as the possible cause of these lung cancers: folate has some interesting and paradoxical effects when it comes to cancer.

This study found that folate may have a "dual-modulator" in colorectal cancer: moderate dietary increases of folate started before any neoplastic foci appear in the colon have a protective influence against colorectal cancer; whereas excessive intake or increased intake of folate after early lesions appear actually increases the formation of tumors.

Thus if you have not got colorectal cancer, folate is protective against this cancer; but if you have early signs of this cancer, folate actually hastens the disease. This likely explains why when folate food fortification was introduced in the US, there was actually a small increase in bowel cancer rates for a few years, but thereafter the bowel cancer rates fell.



Another thread on this subject is found here.
 
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Hip

Senior Member
Messages
17,824
This certainly isn't a randomized trial and you have to consider the characteristics of the people taking the B12 and reasons for taking it. For example, B vitamins are often prescribed to alcoholics (among whom smokers are over-represented, looking particularly at the lung cancer comment), and people with pernicious anaemia (an autoimmune disease) or on long term acid suppressing medication, who cannot absorb dietary B12 properly. These groups may have risk factors for disease that don't apply to other populations. People self-supplementing are often doing so because they already have some kind of symptom or health concern, or know that they eat a limited diet for example. I would say that association in this case certainly doesn't mean causation.

That was also my first thought, and for the Washington 2017 study of 77,118 participants, I don't think it was randomized.

So that's a valid point that you made.

But then again, if that point were true (that people who are already at higher risk form lung cancer might be attracted to taking vitamins), you might expect an equal increase in lung cancer for both men and women taking these vitamins. But there is no increase risk for women, just for men.



Note however, the Norwegian study of 3416 patients I mentioned above was randomized and placebo-controlled. So in this study, patients were blindly assigned by the research to taking either the B12 and folate protocol, or placebo. They did not choose themselves whether to take the vitamins.



It's interestingly to note that the Washington study found that there was no increase in lung cancer among men taking multivitamins which contained B12 and B6, just when these B12 and B6 supplements were taken as individual pills.

One might speculate that this may be due to a vitamin imbalance caused by taking individual B vitamins; but when you take a multivitamin, you are getting a more balanced set of vitamins.
 
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RWP (Rest without Peace)

Senior Member
Messages
209
@Wonkmonk

I should add a point #4. This is a key point. I will elaborate more later with citations.

4. Pursue a professional-grade herbal antiparasitic program that kills a wide range of classes of parasites, such as Ascaris and other B-vitamin-depleting organisms.

Dr. Clark's 1999 cancer book, p. 163, "B12 is needed in amounts much larger than was thought necessary in the past. In fact, cancer patients have a serious deficit. Some of the body's deficit is due to the constant malonate detoxification. But some may be due to Ascaris parasites. They eat it---even turning pink from it!"

RWP