Vitamins and Supplements: Ten Dangers That May Surprise You

In a new report in its September issue and online at www.ConsumerReports.org, Consumer Reports identifies ten hazards that might surprise the large swath of American adults—more than 50 percent—who take vitamins, herbs, or other nutritional supplements.

“Patients sometimes assume that supplements are safe because they are ‘all natural,’ but not all supplements are truly natural. In fact, one of the greatest safety hazards to consumers involves supplements that have been spiked with prescription drugs or toxic metals,” said Jose Luis Mosquera, M.D., medical adviser, Consumer Reports, and an internist who specializes in integrative health and medicine.

Consumer Reports identifies ten hazards distilled from interviews with experts, published research, and its own analysis of reports of serious adverse events submitted to the Food and Drug Administration (FDA), obtained through a Freedom of Information Act request. Here are some of the hazards discussed in the report, plus advice for staying safe:

Supplements are not risk-free. More than 6,300 reports describing an excess of 10,300 serious outcomes, including 115 deaths and more than 2,100 hospitalizations, 1,000 serious injuries or illnesses, 900 emergency-room visits, and some 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. CR notes that the reports 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.

Protect yourself: Search the FDA’s website at www.fda.gov for warnings, alerts, or 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 www.fda.gov/medwatch.

Some supplements are really prescription drugs. According to Daniel Fabricant, Ph.D, 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 Dr. Mosquera.

Protect yourself. Consult your doctor if you are having trouble in the bedroom (it could indicate an underlying health problem). 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,” says Dr. Mosquera.

Protect yourself: Using information from the labels on the supplements and food you routinely consume, add up your daily exposure to everything, and then check CR’s “How much is too much?” table to see if you’re overdoing it.

You can’t depend on warning labels. 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 City metropolitan area, Consumer Reports found wide variations and inconsistencies in labeling.

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 www.ConsumerReports.org/health 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 report notes that the widely held view that fish-oil pills help prevent cardiovascular disease hit a snag when a study of 12,500 people with diabetes or prediabetes and a high risk of heart attack or stroke found no difference in the death rate from cardiovascular disease or other outcomes between those given a 1-gram fish-oil pill every day and those given a placebo. These findings were published in a June 11, 2012, issue of New England Journal of Medicine online report.

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 heart-attack risk compared with those who didn’t use supplements, as reported in the June 2012 issue of the Journal Heart.

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