Allowances (RDAs) and the Tolerable Upper Intake Levels (ULs) are not compatible.
Limitations of the Adequate Intake (AI) were raised by a number of speakers. In Dr. Suttie’s view, the AI is based on a concept that is useful in situations where data are insufficient to set an Estimated Average Requirement (EAR), but the usefulness of the AI has been limited by lack of a common definition. The AI was established in different ways for various nutrients, and the lack of consistency causes some problems. Over the course of 10 to 12 years, new challenges have arisen. For example, should the EARs now be based more on criteria that relate to health promotion? In many ways, the use of such criteria is much more difficult than focusing on biological assays.
One cannot underestimate the impact that the rapid move to genomics will have on the DRI process. Within a few years, it will be relatively inexpensive for people to have their genome searched and at least a few hundred markers identified. Some of those markers will identify rather drastic changes in nutrient metabolism or in the nutrient requirement. How should this type of information be incorporated in the DRI model? How do we make sure that we cover the subpopulations that have higher requirements without moving to higher recommendations that potentially could have some undesirable effects?
More information is available now on how the DRI process can be used for planning and how it is used by different agencies to develop different programs. Some problems have been identified that need to be addressed more explicitly than was done in the first reports.
Recommendations for infants and children definitely need attention. Problems with extrapolations are of concern. Since the methods to study nutrient requirements in adults typically have involved invasive techniques, studies of children pose difficulties. Therefore, addressing the requirements of infants and children will require much more thought in the future. One possibility would be to have a committee address the problem of establishing requirements for infants and children across the range of nutrients.
The difficulties in dealing with ULs need to be addressed, especially since ULs are expected to become more important in the future.