4 ways to avoid supplement dangers

Vitamins and minerals can pose risks

Published: August 2013

Three-quarters of Americans who take multivitamins or other dietary supplements use one or more of the pills in the regimen "to stay healthy," according to a nationally representative survey of 1,022 U.S. adults conducted in May 2013 by the Consumer Reports National Research Center. But there's little evidence that supplements help prevent disease in already healthy, well-fed people. The survey turned up other behavior that was unhelpful at best and risky at worst. Here are our tips for making sure you use supplements safely.

1. Tell your doctor about supplements

Sixty-nine percent of respondents have told their doctor what they're taking. Main reasons others didn't: They hadn't noticed any problems since starting vitamins or supplements, or just didn't think sharing was necessary. But patients should provide a list of all supplements at every visit as part of their medical history, says Pieter Cohen, M.D., an internist at Cambridge Health Alliance in Massachusetts with a special interest in supplements. "There's no question that high doses of vitamins can hurt you," he says. Too much vitamin E, for example, can increase the risk for prostate cancer. Read "10 Surprising Dangers of Vitamins and Supplements" for more details.

2. Watch for drug interactions

Just over a third of those taking multivitamins or other supplements along with prescription medications said they checked with a pharmacist before taking at least one of those drug combinations. But drug-supplement combinations can be dangerous. The popular herbal supplement St. John's wort, for example, can make birth control pills and heart medications less effective, research shows. Help prevent potential interactions by asking your pharmacist to add the supplements you take to your patient profile, says Sophia De Monte, R.Ph., a spokeswoman for the American Pharmacists Association.

3. Don't bother with multivitamins for kids

Forty-eight percent of people with a child under 18 at home said that their youngest child was taking multivitamins at least occasionally. Of those, 73 percent said one of the main reasons was to help kids "stay healthy in general," and 39 percent said it was "to balance their diet." But the American Academy of Pediatrics (AAP) believes that "supplemental vitamins are probably unnecessary for the healthy child who is more than 1 year of age and is consuming a healthy, varied diet," says Neville Golden, M.D., chief of adolescent medicine at Stanford University School of Medicine and a spokesman for the AAP. "A multivitamin containing the recommended daily allowance is not harmful but can be expensive." Read "Do Kids Need Vitamins and Supplements?" for more information.

4. Be skeptical of claims

Fifty-five percent of American adults think that supplement labels must warn about potential dangers and side effects. Wrong. The Food and Drug Administration doesn't require warnings on supplements, with one exception: Those that contain iron must warn about accidental overdosing and fatal poisoning in children. What's more, 47 percent of Americans think the FDA must review products before they're sold to the public, and 45 percent think that claims about safety or effectiveness must be based on solid scientific evidence. But federal law does not require that dietary supplements be proved safe to the FDA's satisfaction or that supplement companies show that most label claims are accurate. Read "Dangerous Dietary Supplements Need Greater Scrutiny and Better Labels" for more information.

Editor's Note:

This article appeared in the October 2013 issue of Consumer Reports magazine.

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