Vitamins are medicine, not magic

Just a reminder: Vitamins aren't inert. They actually do things in your body and we don't totally understand yet what all they do, how they do it, and how much extra vitamin supplementation is too much. Meanwhile, the vitamin and supplement industry remains largely unregulated. Most doctors probably wouldn't tell you to stop taking vitamins, but the concerns voiced by Dr. Paul Offit in a story at CNN aren't ridiculous and should help convince you to make sure that you're talking with your doctor about the supplements and vitamins you take, and to be leery of megadosing on any vitamin.


  1. The whole concept of “megadose” is pretty much wrong.

    The RDAs are based on analysis of flow through the body… and since the body stores some things and can manufacture others, you don’t need to hit 100% of everything every day. On the other hand, getting 200-300% of most of those is unlikely to hurt you any more than overeating would.

    So a basic 100% supplement is unlikely to do harm. But it may not do any good, depending on what the rest of your average diet looks like.

    When you go beyond that, you aren’t supplementing your diet, you’re medicating. Yes, the body can eliminate excesses of some of these, but at the very
    least that ties up channels/energy that could be processing other
    things. Remember, anything can have side effects and the higher the dosage the more likely they are. (Overdose on water and your electrolyte balance goes haywire –a friend who had that experience says you really don’t want to try it.) 

    If your doctor recommends a higher dosage of something, great. If not, why are you assuming you (or, worse, the maunfacturer and advertisers) know more than they do?

    Caveat emptor. More is NOT automatically better.

    1. Mostly to placate my wife, I take a children’s chewable multivitamin without iron. As an American male, I get too much iron as it is (even as a mostly vegetarian — bacon is a vegetable).  Gives me an ~50% RDA on most of the primary vitamins and minerals…

      Several vitamins/minerals follow a hormetic effect — a little does good, but more does harm…

      1. I should add that I do “mega-dose” with some of my favorite anti-oxidants — dark chocolate and dark beer…

    2. Yeah, I’ve had unpleasant side effects from some of the GNC mega-multivitamins. These pills had most vitamins in the 1,000% RDA range, and some nearly 10,000%, which is just ridiculous. Other brands I tolerate fine, but when my preferred line got discontinued recently, I started researching other brands. The problem was that each one has entirely different proportions of each vitamin. Some have a lot of B-complex, but less A, while others are exactly the opposite, and so on. At this point I concluded that it’s probably pseudoscience, and just started eating more vegetables.

      Also, I’ve used megadoses (several grams) of ascorbic acid to try to fight off colds. Whether it’s effective for that is still not clear, but it certainly has an effect on me: causes diarrhea and feels mildly trippy. And it makes my hands smell metallic.

  2. My ex sister-in-law showed up at our house one day and she was orange.   Not tanned but visibly the colour of a mandarin.  Beta-carotene.  Extremely large doses.  Taken to try and thwart the return of breast cancer.

  3. …megadosing on any vitamin…

    Something that has been sold on this blog in the past…

    I can attest to not megadosing on vitamin C.  I did that accidentally during a ‘flu (between tablets and Emergen-C, the latter of which I’d been taking for the Zinc, I was around ~1500%) a while back and it gave me nasty runs for several days.

  4. However, oxidation is necessary for life, and preventing too much of
    this process can be a bad thing because cells that need to be destroyed,
    such as cancer cells, won’t be.

    I have wondered over the past 10-20 years whether the anti-oxidant craze would result in radiation workers having an increased incidence of cancer.  Probably cant do a large enough study to see an effect, but would be interesting to see if a change could be detected.

  5. It’s worth remembering that we call these “vitamins” because 100 years ago, that was the name scientists gave to the hypothetical substances they were looking for: nutrients of which poor people were being deprived by their diets, whose absence from their diets was causing them various diseases.  

    By identifying the vitamins, scientists were able to alleviate the suffering of many poor people, and that is a good thing, but for the average person fortunate enough to have the means to read BoingBoing this afternoon, a much better approach is “don’t eat a the diet of an Edwardian pauper.”

    1. You say that now, but I hear the Edwardian Pauper diet is coming on in a BIG way. Pfft, take that Paleo Diet. (Side effects include scrappy street urchin sense, the ability to work 14 hour days, polio, and black lung.)

    2. Still about one out of ten, to one out of twenty Americans not getting enough of significant vitamins, so not that rare.
       But you touch on an important point:  There is not a good biochemical rationale for these chemicals to be stuck in the same category.  

      1. Oh, I agree. It’s particularly hard to rely on food stamps and not wind up with some vitamin deficiency. 

  6. One really needs to take blood tests to be sure on some of them.  I’m taking 5,000 IUs of vitamin D daily (according to the label, in reality…), and yet I’m not that much above what the doctor wants it.  Funny for a Floridian to need to be taking D…

    1. I live in Palm Springs, which offers even more UV than Florida. My Vit D level was 10, with a normal range of 30-120. Because, of course, it’s too fucking hot and bright to go outside.

    2. Stop slattering yourself with sunscreen and you’ll be fine. Taking a walk around the block with short sleeves in the summer neatly takes care of all your vit D needs. And oh, it does have to be synthesized from something… Read it up.

      1. Your characterization of a block’s worth of sun on your forearms being sufficient is wrong. Many people also live at latitudes where it’s virtually impossible to get enough sunlight for most of the year. And some of us are at high risk for skin cancer and don’t have that option. But please do continue spewing your smug pseudo-scientific theories.

  7. Might look into early “mega-dose” pioneer and certified genius Linus Pauling. He advocated for substantially higher doses of vitamin C than the RDA. Sure, he’s under fire (like everyone else in the “alternative medicine” field) from sites like Quackwatch, but I’d listen to what the two time Nobel laureate had to say and be leery of misinformation and faulty studies. He believed humans and early primate ancestors lost the ability to synthesize C in the body, putting us in a state of nearly chronic deficiency (it is said an average goat generates up to 18,000 mg per day, for example). The RDA was set to prevent serious illness but not to what humans could use to achieve optimal health. Pharmaceuticals even when under the lawful guidance of honest physicians tend to have a greater potential for harm than over-the-counter vitamins.

    1. That’s why I always get my local Nobel Price winner George Smoot to fix my car. He’s obviously better at everything. Mechanics make fun of me, but none of them have a Nobel Prize, so what do they know?

      1.  Well, yes, funny.  But Linus Pauling did get a Nobel in chemistry, so not really analogous.

      1.  There is evidence to the contrary: — Offit makes some compelling points and I will read his book, but the tone of his writing bothers me. It’s true Linus Pauling did die, and he did die of cancer, but to describe it the way he does is cruel and unfair. I don’t think anyone believes his or his wife’s cancer were side effects of Vitamin C use. Why would a professional author insinuate that? The passage feels contemptuous and suggests bias. It’s not certain that C helped Pauling to live as long as he did (94 I believe) but he died more brilliant and more kind than Offit.

        1.  Hardly compelling.   While it may be that the book cited in that rather old article refers to proper studies which support its hypothesis, I doubt it. One of the authors seems to have published a lot of books on similar themes, including one on ‘an orthomolecular approach to cancer’.  Sounds like cargo cult science to me.

          Your preference for tone over content gives me cause for concern.  Medical charlatans have long used charm to conceal their lies and you seem to lack natural defences.

          I prescribe megadoses of skepticism.

  8. saying vitamins are ‘medecine’ is equivalent to saying an apple is medicine.

  9. A topic that interests me is the relationship to Vitamin C and RSD/CRPS.  Reflex sympathetic dystrophy or Chronic regional pain syndrome is an extremely painful, difficult to treat pain condition that comes after different kinds of physical trauma, usually in the extremities.  There mechanism of action isn’t known, but studies suggest that people who supplement with Vitamin C after a  wrist fracture have significantly less likelihood of getting CRPS.  Yes, more study would be good, but I don’t think it’s bad after a fracture to supplement, 500 mg is the recommended dose.

  10. Too much vitamin A will kill you. I verified this in a junior high science fair project that would never fly today, since you apparently can’t cause the death of experimental subject mice any more. Fortunately–so I’ve been told–only one food item in nature has fatal levels of vitamin A: polar bear liver. Supposedly the Inuit have to bury it to keep their dogs from eating it.

    1. So will Vitamin D. If I remember correctly, neither A nor D are water soluble. You can kill yourself with Vitamin C as well, but it’s water-soluble so it’s a little easier to get rid of.

      1. Yeah, but vit A overdose is many orders of magnitude more dangerous, and easier to achieve, than its D counterpart… Recommended RDA is 400 IUs while the body synthesizes up to 50,000 IUs (!!!) if you spend a day out in summer sun… with no ill effects due to hypervitaminosis. You really have to go all out to kill yourself with vit D supplements – basically it’s easier to off yourself with superhydration, for example…

  11. Regulating the vitamin supplement industry will only go so far, since different bodies react differently to the same intakes. What we need in addition is simple, quick, inexpensive and minimally invasive end user technologies for testing and, ideally, monitoring ones bodily health status. Can anyone here recommend anything like that? (I do have a thermometer but that’s about it.)

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