Assessing dietary supplements: evidence helps clarify alternative medicine.(Clinical Rounds)

LA JOLLA, CALIF. -- Vitamins, soy protein, chondroitin, and other dietary supplements once thought to be of dubious therapeutic value are playing a growing role in medical practice, thanks to evidence supporting their use, speakers said at a meeting on natural supplements in evidence-based practice sponsored by the Scripps Clinic.

The speakers reviewed the data behind the claims for many supplements, warned about products known to have harmful effects, and reported on some emerging supplements that show promise.

Diabetes

Having diabetes was an independent predictor of complementary or alternative medicine (CAM) use in a study of 825 people who participated in the 1996 Medical Expenditure Panel Survey, noted Dr. Jay Udani, medical director of the Northridge Hospital Integrative Medicine Program, Northridge, Calif.

The subjects with diabetes were 60% more likely than nondiabetics to use CAM. Among people with diabetes, those with education beyond high school and age of at least 65 years were the most likely to use CAM (Diabetes Care 25[2]:324-29, 2002).

It's the physician's job to ensure that patients don't abandon their hypoglycemic medication in favor of CAM, Dr. Udani said at the meeting, cosponsored by the University of California, San Diego.

Encourage patients with diabetes to take a daily multivitamin supplement, he advised. Diabetic patients tend to excrete large amounts of zinc, chromium, and magnesium. That may help explain why a randomized, double-blind, placebo-controlled trial of 130 people with diabetes showed that those who took a multivitamin and mineral supplement reported fewer infectious illnesses and fewer days lost from work than did those in the placebo group (Ann. Intern. Med. 138[5]:365-71, 2003).