This isn’t really anything new, but Emily Anthes has a nice summary in Slate today of what we currently know about the effectiveness of nutritional supplements–namely that they don’t consistently show any clear benefits except in a few very specific situations:
Vitamins–with their promise to bridge the gap between the nutrients our bodies need and those they get–have always seemed reassuringly simple: Just pop a multivitamin and let your body soak in those extra nutrients. But not any longer. During the past few years, study after study has raised doubts about what, if any, good vitamins actually do a body. They could even pose some real medical risks.
In fact, the reports littering the ODS site seem to converge upon the same point: There is some good news for supplements, but it’s extremely limited. The 2006 NIH panel, for instance, concluded that postmenopausal women should probably take calcium and vitamin D to safeguard their bones; that pregnant women should keep taking folate; and that adults with age-related macular degeneration, an eye disease, should take a combination of antioxidants and zinc. But beyond that, the panel’s strongest recommendation was that scientists conduct further research on the risks and benefits of vitamins. For every study that turns up disconcerting vitamin side effects, there seem to be two more that conclude that we simply don’t know enough yet about supplements to make evidence-based recommendations.
Until we do, we should stop treating supplements like health candy and more like prescription meds, to be used only when there’s a demonstrated need. Doctors should create individualized regimes, tailored to a particular patient’s deficiencies. As for the rest of us, we can put the pills back on the shelf and save our cash for one of those martinis.
So common is the incorrect conventional wisdom on this topic that I too, like so many others, once upon a time regularly took a daily multivitamin. But, I stopped a few years ago, and I’d suggest the same to you… unless you enjoy throwing your money away. If you’re not totally convinced, or if you’d like to read more in depth on the subject, I’d encourage you to take a look at Ben Goldacre‘s book Bad Science, which covers the topic in his characteristicly thorough but quite enjoyable manner. The book still hasn’t been published in the US, but you can find it online.