are vitamins a waste of time?

(CNN) -- More than half of all adults in the United States take some sort of multivitamin; many do so in hopes of preventing heart disease and cancer or even to aid with memory.

But an editorial published in this week's Annals of Internal Medicine says that using supplements and multivitamins to prevent chronic conditions is a waste of money.

"The (vitamin and supplement) industry is based on anecdote, people saying 'I take this, and it makes me feel better,' said Dr. Edgar Miller, professor of medicine and epidemiology at Johns Hopkins University School of Medicine and co-author of the editorial.

"It's perpetuated. But when you put it to the test, there's no evidence of benefit in the long term. It can't prevent mortality, stroke or heart attack."

The editorial, "Enough is Enough: Stop Wasting Money on Vitamin and Mineral Supplements," is based on three studies looking at the effects of multivitamins on preventing heart attacks and cancer, as well as improving cognitive function in men older than 65. All three studies were also published in this week's Annals of Internal Medicine.

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Dr. Roizen responds.

The headlines that appeared would make me go to my doc with questions were I you (and my or your doc may have not read the fine print) … or maybe I'd just say to myself, "I don't need these and stop 'em". And whenever new studies in this area appear, especially headline-making studies, I review 'em in detail to see if my recommendations should change. I need to be responsive to the data, but that requires the work of reading the studies and the fine print in the studies.

These news headlines (headlines like "Are Multivitamins a Waste of Money?," "Vitamins Should Be Avoided" and "Your Multivitamins aren't Doing a D**n Thing" ) and even the editorial in one of medicines leading journals – the Annals of Internal Medicine – do mislead unless you are a fine-print reader. And the news headlines did not mention the fine print.

So I wanted you to know what the fine print said so you were not misled. And so you didn't throw those babies – your multivitamins, your vitamin D3 and four other supplements I'll elaborate on in future blog posts – out with the bathwater.

What the fine print said were that all those people in these studies had normal nutrition and had no vitamin deficiencies, were not potentially or actually pregnant and weren't tested for quality-of-life issues like eyesight. And the news media ignored the significant 8 percent reduction in non-prostate cancers for men over 50, significant 18 percent reduction in non-prostate cancers for men over 70 and the non-significant (because they didn't study enough people) 11 percent reduction in cardiovascular events and deaths (of a high-dose vitamin regimen compared with a low-dose one – yes, everyone in that study received vitamin supplementation).

Yes, the studies had that in the fine print. The editorial noted some of this, but left out the importance of vitamins to eyesight and to preventing 40 percent of autism, 60 percent of childhood cancers (up to age 6) and over 80 percent of congenital defects; it also left out that the cardiovascular study was of a high dose versus a low dose of some vitamins and minerals to prevent deficiency.

My take: You still will benefit from taking half a daily multivitamin containing important nutrients at levels close to their recommended daily allowance twice a day if you are potentially going to become, or are, pregnant, or as an insurance policy against an inadequate diet in people over 50 or if you care about your eyesight (add 900 milligrams of DHA plus 10 milligrams of lutein and 2 milligrams of zeaxanthin a day – more on that in the next blog or two in this series).

So I think half a multi twice a day is a great, inexpensive insurance policy against an imperfect diet. If you think an 18 percent reduction in cancer rates is worth it when you hit age 70, then you should too. And certainly all women who are possibly going to be pregnant, should.

*** [8/15/14]  see also http://kulasoft.blogspot.com/2008/08/to-supplement-or-not-to-supplement.html