Vitamins: Good for You, Bad for You, or What?

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This week research came out in theJournal of the American Medical Association (JAMA) suggesting that taking a daily multivitamin may reduce the incidence of cancer in older men (specifically, the study concluded: “daily multivitamin supplementation modestly but significantly reduced the risk of total cancer”).

On the face of it, this seems like good news for the vitamin industry and has probably already boosted sales.  But, we really need to examine these findings within the larger context of what research has indicated about vitamin supplementation in recent years.

A 2008 study of 15,000 participants showed that taking the vitamins E and C had no effect on cancer rates.

Another study of 35,000 men, conducted just a few months before that one, showed that taking vitamin E and selenium had no impact on cancer rates, and the researchers actually stopped the study early because there appeared to be a slight increase in cancer and diabetes among study participants.

Then, in November 2008, another study of nearly 15,000 participants indicated that taking vitamins C or E  had no impact on the incidence of heart attack, stroke, congestive heart failure or angina. Researchers tracked results over eight years.

A year prior to that, in a study also published in JAMA, researchers concluded that taking vitamin B12 supplements are not effective in preventing strokes, heart attacks or death in people with a history of vascular disease.  In this case, the study was a review that covered 12 studies with 16,598 participants who had pre-existing illness.

Then in 2011, a whopper of a study was published in the Archives of Internal Medicine indicating that multivitamins, folic acid, iron, copper, magnesium, zinc, and vitamin B6 supplements all increased an older woman’s risk of dying from any cause.  This was an observational study of roughly 16,000 women, so it was not able to establish a cause and effect relationship between taking the supplements and death, but the correlation was significant.

It’s worth noting, however, that in the same study, calcium supplementation was associated with a reduced risk of death.

To round things out, it’s also helpful to take a look at this September 2012piece in Consumer Reports that describes 10 dangers of vitamins and supplements.

So, yes, the most recent research shows a modest reduced risk of total cancers among older men taking a multivitamin, but the overall research track record of vitamin supplementation isn’t as encouraging.

The best policy is to do your homework before taking a vitamin or supplement and don’t start taking one just because it seems like the healthy thing to do. As the research shows, it may very well not be.

 http://www.forbes.com/sites/daviddisalvo/2012/10/19/vitamins-good-for-you-bad-for-you-or-what/