Decision to Continue to Monitor. When review of information, either at the initial review step or as a result of an integrative evaluation, indicates a lower level of concern, FDA should continue to monitor information it receives relative to the dietary supplement ingredient. Monitoring consists of either passively watching for new signals of other concerns about the ingredient, as well as maintaining search strategies to routinely search the scientific literature for new data to address specific existing concerns or to identify new concerns. FDA relies on the industry to perform this function in the case of drugs as part of the required postmarketing surveillance; since there is no required postmarketing surveillance for dietary ingredients, ongoing assessment of relevant literature is thus FDA’s responsibility.

Given the variety of types of information that are likely to be available, the Framework classifies scientific information into four broad categories for use in determining the potential for serious harm for a specific dietary supplement ingredient (see Box ES-3):

• human data,

• animal studies,

• information on related substances, and

• in vitro experiments.

Individual chapters describe the types of information that may be available in each of these data categories and considerations for using the different categories of data in evaluating the potential of a dietary supplement ingredient to cause harm (Chapters 4 through 7). Also described are how to consider the potential for dietary supplement interactions with drugs and other xenobiotics⁶ (Chapter 8), important considerations that should be factored into evaluations when vulnerable populations consume dietary supplements (Chapter 9), and considerations for integrating the available data from various sources to weave together the information to determine an overall level of concern (Chapter 10) using a causal model diagram.

The Framework also includes a qualitative method to evaluate the nature of the evidence for a specific piece of information within a particular