Bunk Multivitamin Research Rears Its Ugly Head (Again)

Every Spring, it seems, there are a flurry of articles published seeking to "debunk" the idea that multivitamins may be good for you. Considering the hundreds of billions of dollars spent annually on certain prescription drugs that have been proven ineffective (I am reminded in particular of a drug commercial stating that depression medications don't work in 2/3 of people) it is a constant wonder to me how many people seem to make it their personal mission to make sure that Americans don't "waste" a dollar a day on a decent multivitamin formula.

For starters, the standard tagline that "we can get everything we need from food" is a blatant misrepresentation of the facts. Of course we can get everything we need from food. But do we? I can tell you that I have yet to find one single person who is getting adequate intake of vitamins and minerals from food. It is not even theoretically possible to do it with less than 2500 calories. Next time somebody chides you about taking a multivitamin, ask them to kindly tell you how to get everything you need from food and watch their smugness vanish in a flash.

While one might reasonably expect an acquaintance to pass along some misinformation without researching the validity of the statement, it is a travesty that people holding themselves out to be nutrition experts continue to spread scientific drivel to the public without even bothering to give it a proper evaluation.

The latest installment of anti-vitamin propaganda is a piece in this month's Reader's Digest entitled 5 Vitamin Truths and Lies. Written by freelance health writer Christie Aschwanden, the article opens with the assertion that taking a multivitamin is like believing in the tooth fairy.

Now what would be really naive is to trust anything that is written about natural or alternative medicine in a publication that receives the majority of its advertising funds from pharmaceutical companies.

The article hearkens back to a February 2009 study of the Women's Health Initiative, published in the Archives of Internal Medicine, which purportedly evaluated the ability of multivitamins to reduce the risk of cancer and cardiovascular disease in women. According to the authors, the study provided "convincing evidence that multivitamin use has little or no influence on the risk of common cancers, CVD, or total mortality in postmenopausal women."

While the study may have provided "convincing evidence" to lead author Dr. Marian Neuhouser, I definitely wouldn't call it convincing. In fact, I would hardly call it evidence.

I must admit a certain bewilderment as to how such a well-published scientist with two degrees in nutritional sciences could overlook the glaring shortcomings of this study design. Moreover, the fact that it was even published in a peer-reviewed medical journal calls into question what kind of double-standards must exist in the scientific community. Apparently, junk science is allowed to pass the AMA's review boards so long as its conclusions support the status quo.

First and foremost, it borders on the absurd to attempt to draw any meaningful conclusions about "multivitamin use" when there are hundreds of different formulations on the market. Unfortunately, the medical community at large continues to accept conclusions drawn about multivitamins as if they were all one and the same. This is akin to performing a cohort study on "all heart medications" to determine if they really work.

Of greater impact than the specific formulation is the variation in bioavailability. Cheap, mass-produced, multivitamins are more likely to pass through the small intestine without breaking down and being absorbed. Part of the reason high quality multivitamins cost more is because they have superior delivery systems designed for improved bioavailability. The best multis also use naturally-derived- rather than synthetic- forms of nutrients. Therefore, the study at most demonstrates that cheap multivitamins confer no benefit, which would be of little surprise to anybody with actual training in the use of dietary supplements.

Secondly, the authors allowed data to be incorporated as long as the participants took a multivitamin at least once a week. Multivitamins are meant to be taken daily. I could hardly imagine scientists conducting an efficacy study on a drug agent allowing the participants to take the drug whenever they felt like it, so long as it was at least once a week. I can't think of any trained practitioner who would claim that taking a multivitamin once a week is going to do much of anything for you. This study would be laughable, if it weren't for so many people taking it seriously.

Finally, anybody who attempts to make a generalized conclusion from this study is either totally ignorant of the scientific method, or being deliberately misleading. The fact that the study concludes that multivitamins have "little or no influence on the risk of common cancers, CVD, or total mortality" means just that.

If you are at a high risk for cancer, cardiovascular disease, or imminent death, you probably need more than a multivitamin to get things back on track. I don't think there are too many practitioners out there telling people that multivitamins are magical pills that can stave off serious diseases and even death. But just in case there are, thanks be to Reader's Digest for watching our backs.