As far as I understand, it is well documented that smoking correlates with B12 deficiency, and so many smokers take this vitamin as a supplement to make themselves feel better about their smoking habits.<p>This study then showed, not just that people got cancer, but they got lung cancer. This study was not a randomized trial that can show causation: it was a cohort study, where they ask a bunch of questions about peoples' past or ongoing behavior and then look for correlations from which you can try to guess at potential causes.<p>In a cohort study, there are attempts to predict confounding variables and "control" for them, but this involves essentially assuming the result and backing out the math, and assumes you trust that the participant is giving you correct data anyway.<p>A really fun confounding variable you get in these kinds of studies is that people who even bother to do your study correctly are also people who probably listen to their doctor and brush their teeth and wear their seatbelts and generally lead a safer life. (I am forgetting the name of this, but it is something like "compliance effect"?)<p>Further, if you have participants who don't just answer poorly but actively lie in ways that are correlated with the variables you care about (maybe "another way I make myself feel better about my smoking habit is to pretend I smoke half as much as I do or also smoke cigars and not count them"), you are effectively going to have no hope of "controlling" for that in the way you can with a blinded randomized controlled trial.<p>Given this, I read this and only think "that's an interesting hypothesis that is now worth digging into with real science to figure out what is going on", not "OK, everyone should stop taking B12 supplements if they don't want to end up randomly getting lung cancer"... that is just way too specific and too predictable of a cancer to be associated with this particular supplement.
Participants took folic acid (lab created), not folate (the form found in nature) which has been shown to be far more absorbable. Folic acid also binds to the folate receptors, preventing folate from food being taken up. In people with MTHFR gene mutations, folic acid is contraindicated. Anyone with such mutations should be avoiding foods with added folic acid. Folate and folacin seem to be ok. MTHFR is already associated with increased cancer and heart disease.<p>No mention was made whether the participants had MTHFR mutations, perhaps because the cohorts started 20 years ago and cheap sequencing wasn't yet available.<p>All it tells is that more actual science needs to be done here. Also the article was classic poor science reporting with obvious bias.
"Regular" people doesn't need in any way of to these B12 supplements, as there is plenty of it in animal products, which have already been taking B12 supplements all their lives.
However, vegans need to take these supplements if they want their B12 intake, without animals as the intermediary.<p>As a side note: B12 is created by micro-organisms in the soil, making our vegetables and fruits completely covered of it. With our modern lifestyle, the soil is terribly poor of these micro-organisms and having cleaned-as-hell vegetables reduces even more the B12 we can find in these vegs.
While this study is looking at lung cancer specifically, it's worth highlighting how much vitamin B6, b12 and other B-family are you getting via energy drinks.
I'm currently hooled on Red Bull sugar free and I believe that long term consumption may be unhealthy for me due to elevated levels of B vitamins:<p><a href="http://nutritiondata.self.com/facts/beverages/9222/2" rel="nofollow">http://nutritiondata.self.com/facts/beverages/9222/2</a>
Full text of the published study: <a href="http://ascopubs.org/doi/full/10.1200/JCO.2017.72.7735" rel="nofollow">http://ascopubs.org/doi/full/10.1200/JCO.2017.72.7735</a><p>Long-Term, Supplemental, One-Carbon Metabolism–Related Vitamin B Use in Relation to Lung Cancer Risk in the Vitamins and Lifestyle (VITAL) Cohort
> There was no apparent risk among women—which is not to say it doesn’t exist, only that it wasn’t apparent.<p>Or it doesn't exist, or it even lowers the risk of cancer in women, or ...<p>I hate when something "not found" in some study is streched to fit some specific tone that the article wants.
As someone with an as yet unexplained B12 deficiency (meat eater, never-smoker, no intrinsic factor antibody) who gets injections via cyanocobalamin every other month I feel like I’ve just been hit with more FUD
I'm surprised the article doesn't mention energy drinks at all. Isn't one of the major selling points of many energy drinks is the amount of B vitamins present? My guess is the amounts the article refers to are much higher concentrations than your average Monster / Redbull / Rockstar.
Vitamin B12 deficiency is common in people who have been vegetarian for many years. (Others usually have a large reserve.) From the speculation in the article, it sounds like they'd be better off taking (normal) doses of it, since it's deficiency or excess that could cause cancer, and not the pills:<p>> Deficiency can also mean genes that should be inhibited are no longer inhibited, also potentially meaning cancer. Sufficiency of certain vitamins is important in cancer prevention, but avoiding excess appears to be similarly important.
I'm not sure why it would be surprising that any supplement can have a bad impact on your body. If you're taking a supplement because you believe it has a potential benefit, it must have some impact on your body so therefore too little or too much must surely be bad as well?
The vitamin industry is scaring people to prop up sales. Eat a more or less varied diet and you'll be fine, unless you have a very specific condition (pregnant for one).<p>Less Vitamin X today is not going to kill you. It's probably better than, "oh I need 1000mg so I'll just take 5000 and let the body handle it."
Such a misleading headline and article, most vitamin tablets (atleast in the UK) contain no more than 1-2mg of either B1 or B12, if anything you're going to get more from eating excessive meat which is a higher risk. This study is extremely suspicious as to who funded both it and whos behind this article.
Definitely worth more research into possible mechanisms, but until studies account for the numerous contamination issues (lead, etc.) that many different home supplements carry, then there is going to be a mystery factor in so many of these studies sending all kinds of mixed signals.
The word excessive needs to be in the title.<p>In 20 years of looking I've never seen a study that links recommended daily allowance amounts to anything harmful.<p>Yes 1000x RDA vitamins should be banned, but incendiary titles muddy people's thinking.
I have a feeling that a lot of these supplements are doing more harm than good. I really wish the FDA would step in and regulate the vitamin market the same way they do with normal medicine like Tylenol, etc.