WSJ.com - The Case Against Vitamins

A comprehensive look at various vitamin trials...

WSJ.com - The Case Against Vitamins: "Recent studies show that many vitamins not only don't help. They may actually cause harm.
By TARA PARKER-POPE
March 20, 2006; Page R1

Every day, millions of Americans gobble down fistfuls of vitamins in a bid to ward off ill health. They swallow megadoses of vitamin C in hopes of boosting their immune systems, B vitamins to protect their hearts, and vitamin E, beta carotene and other antioxidants to fight cancer.

It's estimated that 70% of American households buy vitamins. Annual spending on vitamins reached $7 billion last year, according to industry figures.

But a troubling body of research is beginning to suggest that vitamin supplements may be doing more harm than good. Over the past several years, studies that were expected to prove dramatic benefits from vitamin use have instead shown the opposite."...

"People hear that if they take vitamins they'll feel better," says Edgar R. Miller, clinical investigator for the National Institute on Aging and author of an analysis that showed a higher risk of death among vitamin E users in several studies. "But when you put [vitamins] to the test in clinical trials, the results are hugely disappointing and in some cases show harm. People think they are going to live longer, but the evidence doesn't support that. Sometimes it's actually the opposite."...

Another concern is that while vitamins from food sources are necessary and good for you, consumers today often scarf down vitamins at levels that are more like a pharmaceutical dose than something found in nature. In a test tube, high doses of a single antioxidant can turn bad, evolving into pro-oxidants -- meaning they start to oxidize and create free radicals, causing the very problem you were trying to prevent.

Here's a look at what science shows about the risks and benefits of some particular vitamins. (read on; subscription required)...