Institute of Medicine Advisory: April 1 public briefing on safety of dietary supplements


WASHINGTON -- To bolster the U.S. Food and Drug Administration's ability to evaluate the safety of dietary supplements, a new report from the Institute of Medicine and the National Research Council of the National Academies outlines a science-based process for assessing supplement ingredients, even when data about a substance's safety in humans is scarce. This approach to safety evaluation works within the regulatory parameters set by the Dietary Supplement Health and Education Act (DSHEA), which does not require manufacturers to provide safety data on their products. However, supplement makers, the public, and others need to increase their reporting of health problems related to supplement use in order to further improve the agency's ability to protect consumers, the report says.

"Approximately 29,000 dietary supplements are currently available to the American consumer, and while most are safe, questions have been raised about FDA's resources to identify and address the occasional problem products," said Barbara Schneeman, chair of the committee that wrote the report and professor of nutrition, food science, and internal medicine, University of California, Davis. DSHEA established in 1994 that dietary supplements are to be regulated like foods instead of drugs, meaning that they are considered safe unless proved otherwise and are not required to be clinically tested before they reach the market. It is therefore up to FDA to determine whether a particular substance on the market is harmful based upon information available in the public domain. "In some cases, data on an ingredient's safety in humans are scant or nonexistent," Schneeman said. "Our report describes how other types of data -- such as the results of tests in animals, or information on similar substances -- can be used in a science-based approach to determine whether a supplement poses a significant risk to human health."

The process provides a way to identify supplement ingredients that may pose risks, prioritize them based on their level of potential risk, and evaluate them for safety. The report categorizes different kinds of data that FDA can use to assess safety and offers guidelines for determining the significance of the evidence available on a particular substance. Given that supplements are assumed, rather than proven, to be safe before they are marketed, FDA does not need direct evidence of harm to humans to take action; rather the agency must show that a product poses an unreasonable risk to users, the report says.

Data from animal studies and validated in vitro tests may provide enough information on their own to warrant FDA action, even without direct evidence of harmful effects in people, the report notes. Furthermore, historical use is not always enough by itself to prove the safety of a supplement, even if it has been consumed for centuries or used in folk medicine, the committee determined. And because changes in how an ingredient is formulated or processed raise the potential for new adverse effects, a reformulated ingredient should be subject to the same regulatory oversight as a new one.

While the process recommended by the committee is designed to help FDA set priorities and carry out evaluations even when data are limited, the report recommends that manufacturers and distributors be required by DSHEA to report adverse events to FDA in a timely fashion to facilitate safety evaluations. Not only do supplement manufacturers not have to conduct pre-market safety tests, they also are not required to collect and report any health problems that they discover once the products are on the market. Lack of reporting significantly hampers the agency's ability to actively monitor supplement safety, the report says. The Office of the Inspector General estimates that FDA receives reports on less than half of 1 percent of all adverse events associated with supplements.

To further boost reporting, labels on supplements should include a toll-free number for consumers and health professionals to call in health problems or concerns related to the product, the committee said. Labels also should include the name and place of business of both the distributor and the manufacturer so that problems can be traced more easily to their source.

In addition, although manufacturers need not seek approval to market a supplement, DSHEA does require them to notify FDA of their intent to introduce a new compound. During this pre-marketing review period, supplement makers and distributors should be required to provide the agency with all available safety data, both favorable and unfavorable, on their new products. This change would not mean that supplement makers would be required to conduct pre-market testing.

FDA must have adequate resources to support the increased workload that implementing a comprehensive safety evaluation process entails. Congress should provide the agency with sufficient funding to collect and analyze data and carry out the consumer protection and education responsibilities mandated by DSHEA.

Annual sales of dietary supplements in the United States are approaching $16 billion. An average of 1,000 new products are developed each year. Although manufacturers are restricted from claiming that using their products leads to therapeutic benefits, surveys show that many people take supplements for purposes such as treating colds or alleviating depression. According to other survey data, the majority of consumers believe these products to be either reasonably or completely safe.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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