study commissioned by the Food and Drug Administration (FDA) estimated that the FDA is notified of < 1% of all adverse events associated with dietary supplements. Among the factors that may contribute to underreporting are that many consumers presume supplements to be safe, use these products without the supervision of a health care professional, and may be unaware that the FDA regulates them. In 2001 an Office of the Inspector General report identified many of the difficulties in evaluating adverse events in a voluntary system and the barriers to effective analysis of these reports to generate possible signals of concern. These include factors such as limited medical information, limited product information, limited manufacturer information, limited information on dietary supplement consumers, and limited ability to analyze trends. In addition, for dietary supplements, vital premarket information (which is available for drug products) is often missing so that possible public health concerns generated by the adverse event reporting system, such as limited clinical information, product identification, and information on consumer use, cannot be adequately assessed. Thus, the FDA is inherently limited in its ability to investigate signals of public health problems generated by the system. However, the FDA can use adverse event reports to identify areas of concern warranting further investigation. The FDA then initiates collaboration with federal partners to identify knowledge gaps in the safety of individual dietary ingredients and products and works with these partners to fill these information gaps to support appropriate regulatory action.
