The types of adverse events reported for dietary supplements are many and varied, compared to the types of adverse events that are related to foods. The etiologies, with respect to dietary supplements, are multiple. With respect to foods, they tend to cluster in food-borne illnesses, pathogen-related problems, as well as sensitivities and allergies. The duration of effects associated with dietary supplements can be either acute or chronic. With respect to food products, they tend to be very acute, again, because of the relationship of pathogens and adverse effects. The information source of the adverse event reports for dietary supplements are predominantly healthcare providers; whereas, for foods, they tend to be consumers. The nature of the adverse events are so severe that people go to their healthcare providers who, in turn, report to FDA. Lastly, FDA is finding that follow-up on dietary supplements is very expensive and requires far more resources than the usual follow-up on food reports, which tend to be much more limited and much easier for them to do.
We are faced with a public health dilemma. Dietary supplements are now very widely used. There is a lack of industry safety and effectiveness research, largely because there is no incentive to conduct research. Under the law, as it now exists, if a substance was present in a traditional product prior to the year 1994, it is not a new ingredient. Therefore, there is no incentive for supplement manufacturers to do any research as to the safety or the effectiveness of the dietary supplement. The medical community and FDA lack knowledge about the safety of these products, their efficacy, and the substantiation for label claims. Lastly, FDA is confined to reliance on post-market surveillance and its own resource-constrained ability to investigate adverse events, which further complicates the medical community’s ability to assemble a substantial database on the safety and efficacy of these products.
When a good base of science helps to inform legislation in areas of public health, we have a good public health policy. In the case of dietary supplements, excluding vitamin and mineral supplements, we do not have a sufficient base of knowledge about their safety or efficacy to inform our current policies. In fact, we have a situation where legislation has created a very perverse incentive against industry investment into the types of research that would lead to wise public policy on dietary supplements.