With nearly one-fifth of Americans taking dietary supplements (search), the Institute of Medicine (search) on Wednesday called for tougher regulations to make sure the products are safe and do what they claim. The institute expressed concern about the quality of dietary supplements, saying "there is little product reliability."

This makes it difficult for health professionals to guide patients in use of supplements, the report said. The panel urged that Congress take steps to require improved quality control of supplements and to provide incentives to study the efficacy of the products.

"Reliable and standardized products are needed," Dr. Stuart Bondurant, chairman of the committee that prepared the report, said at a briefing Wednesday.

In a 327-page report, the institute also urged that complimentary and alternative medical procedures, such as herbal remedies and acupuncture (search), be required to meet the same standards of effectiveness as conventional medical treatments.

Dr. Stephen E. Straus, director of the government's National Center for Complimentary and Alternative Medicine (search), said requiring the same research standards "will further the scientific investigation of this new field, increase its legitimacy as a research area and ultimately improve public health."

Unlike drugs, which must be proven safe before they can be sold, the Dietary Supplement Health and Education Act (search) allows sale of supplements unless the Food and Drug Administration can prove them harmful. The law also does not require manufacturers to report adverse reactions, as drug companies must.

Sen. Tom Harkin, D-Iowa, who has pressed for more FDA attention to supplements, believes that manufacturers should be required to report adverse events and continues to urge action against false or misleading claims, according to spokeswoman Allison Dobson.

The Institute of Medicine report said 18.9 percent of Americans reported in 2004 that they had taken a dietary supplement in the past year. The industry was responsible for $18.7 billion in sales in 2002.

A study by researchers at Harvard Medical School, also being released Wednesday, found that about 35 percent of Americans have used some form of alternative medicine

Dr. Hilary Tindle, lead author of that report, said such widespread use shows the necessity of studying the safety, efficacy and cost-effectiveness of these approaches.

The biggest change was an increase in use of herbal supplements (search) over the five years, the study said. The practice of yoga also increased.

The Harvard report, published in the journal Alternative Therapies in Health and Medicine, said use of therapies such as acupuncture, biofeedback (search), energy healing (search) and hypnosis remained essentially unchanged between 1997 and 2002, while the use of homeopathy (search), high-dose vitamins (search), chiropractic and massage therapy declined slightly.

Both the Harvard and IOM reports cited a failure of a majority of consumers using supplements to tell their doctors.

"This is especially critical as more becomes known about the adverse effects associated with individual dietary supplements as well as their interactions with prescription drugs," said Harvard's Tindle.

The Federal Trade Commission has reported a flurry of unfounded or exaggerated claims for supplements, the IOM report notes. It calls on Congress and federal agencies to set standards for manufacturing quality.

The Institute of Medicine is a part of the National Academy of Science, an independent organization chartered by Congress to advise the government on scientific matters. The National Center for Complimentary and Alternative Medicine, which requested the IOM study, is part of the National Institutes of Health.