No Precautionary Principle When It Comes to Dubious Vitamins

May 17, 2007 | Updated May 25, 2011

Yet again, another study points to the dangers of vitamin supplements. The latest study, published in the Journal of the National Cancer Institute, found that heavy use of multi-vitamins doubled a man's risk of dying of prostate cancer. The study is by no means conclusive. And any college level science major could point to problems with this study and it's conclusions, tentative as they are.

But this is not the first time that peer-review journals have found risks associated with vitamins and supplements. Just last year we learned that antioxidant vitamins do not reduce pregnancy-related high blood pressure, and may in fact increase the risk.

And the July 2004 issue of Pediatrics, the journal of the American Academy of Pediatrics, told us that multi-vitamin use within the first six months of life is associated with a higher risk for asthma in black infants. It also found that vitamin use at age three was associated with an increased risk for food allergies. That came on the heels of a May 2004 report that antioxidant vitamins may sometimes be harmful for the heart. And a June 2004 report that suggested a link between vitamin C and arthritis.

Still, no public health advocacy groups are calling for people to stop taking multi-vitamins until we can be absolutely sure they are safe. The notion of such advice may even seem preposterous to you. But should it? Are vitamins somehow intrinsically safe? Should they be treated as safer or healthier than other products?

For instance, if this study had found that it was eating French fries rather than taking vitamins which increased cancer death risks, this would be headline news, activists would harp, and lawsuits would follow.

Why does the precautionary principle apply to foods and chemicals, but not to vitamins? Why the difference? Should it apply at all? Think about it next time someone tries to trick you into buying into the seductive but unwise precautionary principle.