Medical Edge Newspaper Column

Dietary Supplements Should Not Be Taken Lightly

December 10, 2007
Dear Mayo Clinic:
My husband is taking vast amounts of dietary supplements, including liquid multivitamin and minerals, Arthro Joint Complex and flaxseed oil. He also takes coenzyme Q10, fish oil, saw palmetto, vitamin E, St. John's wort, silymarin, Super Green and chromium picolinate, among others. His prescription medications include Hytrin, allopurinol, and Lipitor. We eat balanced, nutritious meals. Does he need supplements? Are they safe?

Answer:
People who are generally healthy and eat a wide variety of foods, including fruits, vegetables, whole grains, legumes and lean meats, don't likely need dietary supplements. But, in some cases, judicious use of vitamins, minerals or herbal supplements can benefit people whose eating or lifestyle habits restrict or adversely affect a nutritious diet. They also may be helpful when other factors, such as age or illness, affect your body's nutritional needs.

Like any other drug, many dietary supplements have active ingredients that can affect how your body functions. If taken for the right indication, a supplement may give you the benefit you are seeking. But when taken with other medications and supplements, they may cause harm. St. John's wort, for example, has been shown to be helpful in reducing depression, however, research also indicates that it can cause serious interactions with other medications and supplements. Thus, most supplements are neither "good" nor "bad"  it is how they are used that generally determines the effects they will have.

Because dietary supplements are subject to minimal Food and Drug Administration regulations, not all are standardized to ensure quality and strength. The good news is that this will change by 2010 when all supplements sold in the United States will have to meet mandatory requirements for purity and quality. Until then, read labels carefully and look for evidence of third party verification of product quality, such as USPV (United States Pharmacopeia Verified) on the label. This designation ensures that the supplement meets the standards for strength, purity, disintegration and dissolution established by the testing organization United States Pharmacopeia. Another company that provides similar services is NSF International, an independent, not-for-profit, non-governmental organization.

Even within recommended doses, some supplements can have unexpected, unpleasant side effects, such as stomach upset and muscle pain. And not all herbal supplements are safe; some have been shown to contain toxic substances, including heavy metals such as lead and mercury. Thus, it is important to treat all supplements with respect and do your homework before considering any new supplement.

I recommend that your husband meet with his physician to review his medical history and evaluate each supplement individually. If his physician isn't familiar with dietary supplements, your husband can request a referral to a pharmacist or specialist who is knowledgeable about them.

 Brent Bauer, M.D., Complementary and Integrative Medicine, Mayo Clinic, Rochester, Minn.