Vitamins and supplements may contain unexpected hazards, based on reports to the FDA. (bigstock)

The more than 50 percent of American adults who take vitamins, herbs or other nutritional supplements may be surprised by some of the hazards that Consumer Reports recently identified. Its findings were distilled from interviews with experts, published research and its own analysis of reports of serious adverse events submitted to the Food and Drug Administration, obtained through a Freedom of Information Act request. Here are some of the hazards:

Supplements aren’t risk-free

More than 6,300 reports — describing more than 10,300 serious outcomes, including 115 deaths and more than 2,100 hospitalizations, 1,000 serious injuries or illnesses, 900 emergency room visits, and 4,000 other important medical events — streamed into the FDA from supplement companies, consumers, health-care providers and others between 2007 and mid-April 2012. Consumer Reports notes that these incidents by themselves don’t prove that supplements caused the problems, but the raw numbers are cause for concern. Current laws make it difficult for the FDA to order a problem product off the market. In fact, to date, the FDA has banned only one ingredient, ephedrine alkaloids.

To protect yourself, search the FDA’s Web site ( for warnings, alerts and voluntary recalls involving a supplement you are thinking of taking. If you suspect you’re having a bad reaction to a supplement, tell your doctor. You can also report your problem to the FDA at 800-332-1088 or

Some supplements are really prescription drugs

According to Daniel Fabricant, director of the FDA’s Division of Dietary Supplement Programs, dietary supplements spiked with prescription drugs are the “largest threat” to consumer safety. Many recalled products have the same or similar active ingredients as prescription drugs such as sildenafil (Viagra), tadalafil (Cialis) and sibutramine (Meridia, a weight-loss drug that was removed from the market in 2010 because of evidence that it increased the risk of heart attacks and strokes). Others contained synthetic steroids. “As a result, adulterated products can cause some of the same side effects and interactions that a consumer may be trying to avoid by opting for supplements instead of prescription drugs,” says Jose Luis Mosquera, an internist who specializes in integrative health and medicine and serves as a medical adviser to Consumer Reports.

To protect yourself, consult your doctor if you are having trouble in the bedroom. And try to slim down with diet and exercise. Build muscle by weight training.

You can overdose on vitamins and minerals

Unless your health-care provider tells you that you need more than 100 percent of the recommended daily intake of a particular nutrient, you probably don’t. Megadoses of the fat-soluble vitamins A, D, E and K can cause problems, and even some standard doses may interfere with certain prescription medicines. “Surprisingly, some people may experience adverse effects from even normal doses of a vitamin or mineral supplement, especially patients with digestive issues or those who take blood thinners,” Mosquera says.

You can’t rely on warning labels — if they’re even there

For one thing, the FDA doesn’t require them on supplements, with one important exception, iron. In a market basket study of 233 products purchased online and in the New York metropolitan area, Consumer Reports found wide variations and inconsistencies in labeling.

To protect yourself, make sure your doctor or pharmacist knows what supplements and prescription drugs you are taking or thinking of taking. You can also check for interactions by using Consumer Reports’ “Guide: 100+ Commonly Used Supplements.” To access the free guide, go to and click on “Natural Health.”

Heart and cancer protection: not proven

Omega-3 pills and antioxidants are widely thought to reduce the risk of heart disease and cancer, respectively, and millions of women take calcium to protect their bones. But recent evidence casts doubt on whether those supplements are as safe or effective as assumed. The widely held view that fish-oil pills help prevent cardiovascular disease hit a snag with the results of a study of 12,500 people with diabetes or prediabetes and a high risk of heart attack or stroke. This study, published online by the New England Journal of Medicine on June 11, found no difference in the death rate from cardiovascular disease or other outcomes between those given a one-gram fish-oil pill every day and those given a placebo.

Consumer Reports also notes a recent blow against calcium supplements by German and Swiss researchers who followed almost 24,000 adults for an average of 11 years. They found that regular users of calcium supplements had an 86 percent increased risk of heart attacks compared with those who didn’t use supplements, as reported in the June issue of the Journal Heart.

To protect yourself, lay off the antioxidant supplements and reduce your cancer risk safely by quitting smoking, avoiding excessive alcohol and eating a healthful diet that includes plenty of fruit, vegetables, nuts, legumes and whole grains.

Copyright 2012. Consumers Union of United States Inc.