A dear friend of mine told me her symptoms and I suggested she speak to her doctor and get tested for b12 deficiency. She did.... and oh my - he was furious and said that b12 causes cancer - she (primed by me with info) questioned this and he told her a new Danish paper categorically states this. He then shooed her out of his surgery. She got back to me.......... any thoughts?

13 Replies

  • Well that means jillc39 that anyone who eats meat, fish, poultry, seafoods, eggs, and dairy produce is doomed to die of cancer which is just "quackers".

    Where does this so called doctor think we get B12 from in the first place? I know where I would like to place my "shoo"

  • Blimey, even the Daily Mule (which is famous for saying that X causes cancer) hasn't included B12 in their list.

  • Apparently it's only Vitamins A, C and E that cause cancer - - while Vitamins A, C, D and E prevent cancer (same link).

  • Oh! my - your dead if you do and your dead if you don't. I give up.

  • There is a definite correlation between higher rates of some cancers and large tumours where people are receiving treatment for B12 absorption problem. However, this is a correlation and no causal link has ever been found. It is quite probable that the reason for the higher incidence of cancer may be down to the fact that B12 deficiency puts you at higher risk of cancer so it was a cancer that was latent before the B12 therapy started. The tendency for larger tumours is probably down to the fact that B12 is involved in cell production and this will apply to cancerous cells as well as non-cancerous.

    Unfortunately your GP isn't alone in not understanding the difference between a correlation and a causal link.

  • The papers I've read tend to put the causation t'other way around - the cancer causes high B12.

  • for some cancers yes but there was at least one study in Scandanavia that showed a high correlation between treatment for B12 and cancers but most medics just don't seem to have twigged that it was a correlation that was reported - hence the reaction of the GP that prompted the post.

  • just one more gp who doesn't know his arm from his elbow = but joking apart its just scary isn't it?

  • Sorry I don't have the link (save so many on B12), but recently read a medical report that confirmed what Gambit says, that LOW B12 can be a cause of cancer and then the treatment might encourage it to proliferate. Maybe this is the paper the doctor meant? Still a strange interpretation imo.

    Because I imagine getting low B12 treated ASAP would be the best form of prevention.

  • This has been misinterpreted. The article clearly states it is looking at naturally high B12 levels as they excluded those on supplements. There is a link between naturally high B12 and haematological or liver cancers, which is not the same as high B12 being the cause. My understanding is that high natural B12 may be a marker for some malignancy though as the carriers of B12 are derived from e.g. malignant bone marrow cells, in the case of a blood cancer.

  • The other mechanism a paper called 'Significance of raised cobalamin' discusses is that in liver damage due to liver cancer etc then that will release excess B12. Again, that is a marker and does not mean it caused the cancer. It is more like a side effect of high B12 occurs if there is an excess of B12 carriers being produced or B12 storage cells being destroyed.

    Alcoholic liver damage causes B12 to be released too. So saying high B12 causes cancer is similar to saying it causes alcoholic liver damage. Yes, there is an association but the mechanism needs to be understood.

    This also is irrelevant for whether or not to test for low B12 and treat it.

    Sorry can't get link to work on phone.

  • Hi Jillc39. Here we go again! If she has symptoms of B12 deficiency, then the doctor should at the very least test her Serum B12.Irrespective of whatever papers he's read - and misinterpreted. Numpty.

    She could fill in the symptom checklist, go back, and insist he takes her seriously or...

    If she's symptomatic and desperate she could get a private test done (though I hate to suggest that 'cause it shouldn't be necessary). At least then she'll know whether to start chasing her doctor for treatment...she'll have 'evidence' and she'll be able to go armed with lots of lovely information from this forum.

    Wish her good luck from us....we'll look out for her posts in due course, if she needs help 😀. Let's us know how she gets on.

    P.s. As he's so well versed in what B12 apparently causes, perhaps he could explain to her what B12 deficiency certainly causes? (Sorry, couldn't resist saying that 😀)

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