Some of the best research on supplements hasn’t been encouraging. (Bigstock)

A 43-year-old dog groomer came to the office of Orly Avitzur, medical adviser to Consumer Reports, complaining of headaches. The patient also had a list of 18 dietary supplements and herbs that she took for fibromyalgia and other problems.

Avitzur had never heard of most of them, and she worried that one, or several, might be contributing to the patient’s headaches. But with supplements, it’s often hard to know since there’s little solid research on them.

Most doctors have had little formal education in alternative and complementary medicine. And truthfully, doctors tend to be wary of supplements and don’t routinely recommend them.

Here are the reasons Avitzur is leery about supplements:

●The benefits are uncertain, and there are few well-controlled studies to support supplements. Many studies don’t take full account of the subjects’ diets, so it’s hard to know whether a benefit really comes from a supplement.

Some of the best research hasn’t been encouraging. A large study published last year in the New England Journal of Medicine, for example, found that people who took fish-oil pills didn’t cut their rate of heart attacks and strokes or live longer than people who took a placebo. A similar study found no benefit from multivitamins.

●Several studies have raised concerns about the risks of supplements, including even some of those previously thought to be helpful. For example, a 2013 study of almost 400,000 people ages 50 to 71 linked supplemental calcium to an increased risk of death from heart disease in men.

And the risks aren’t limited to people in studies. Avitzur reports having seen patients harmed by supplements. A 44-year-old with muscle cramps, for example, had recently started taking creatine, a chemical produced by the body that’s also sold as a bodybuilding supplement. A blood test showed an elevated level of muscle enzymes. When he stopped taking it, the cramps stopped, too. And a 30-year-old who took another “bodybuilder” supplement containing arginine nitrate got a severe headache the first time he took it; the second time, he developed a serious bleed in his brain.

●Some drugs and supplements don’t go well together. Ginkgo biloba and Vitamin E, for example, can cause bleeding and shouldn’t be taken with blood thinners or aspirin. And St. John’s wort can interact with many drugs, including those used to control depression, seizures and an overactive immune system.

●The government doesn’t carefully regulate supplements. In a survey of 1,022 U.S. adults conducted by the Consumer Reports National Research Center last year, 55 percent thought that the government required companies to include warnings about the potential dangers and side effects of supplements. And 47 percent thought that the government must review the products before they go on the market. Wrong on both counts. Sometimes it’s hard to know which ingredients supplements contain unless patients bring them to the doctor’s office. That was the case with the dog-groomer patient, who listed “joint formula,” “B-75 stress” and “digestive enzymes” on her drug form. Even if you have the bottle, that’s no guarantee that the product contains what it claims to have — or that it isn’t contaminated with heavy metals, pesticides or drugs.

What to take instead

●Get your vitamins and minerals from food. Pills may seem like an easy answer, but it’s better to eat a varied, healthful diet. Because of the growing concerns about calcium pills and heart disease, for example, many physicians now say that healthy people should get calcium from food only.

●If you do buy a supplement, look for the “USP Verified” mark. It indicates that the manufacturer asked the U.S. Pharmacopeia, a nonprofit, standards-setting organization, to verify the quality, purity and potency of its raw ingredients or finished products. USP maintains a list at

●Avoid doctors who sell you products. The American Medical Association says that physicians who distribute them should provide them to patients free of charge or at cost.

●Talk with your doctors. More than a quarter of the survey respondents didn’t let their doctors know about all of the vitamins or supplements they were taking. That’s a mistake, since the discussion can help your doctors understand your preferences as they work with you to develop a treatment plan.

That is what Avitzur did with her headache patient, who gradually eliminated some of her supplements. Over time, her headaches also abated. Coincidence? It’s hard to say for sure — and that’s part of the problem with supplements.

Copyright 2013. Consumers Union of United States Inc.

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