The RDA concept: time for a change?

Fifty-one years ago, at the height of World War II, the National Research Council (NRC) published a six-page document entitled Recommended Dietary Allowances (RDAs). Since then, the nine successive editions of the RDAs have become nutrition's gold standard—the most authoritative guide to the nutrient needs of people in the United States, used for an extraordinary variety of purposes. The NRC's Food and Nutrition Board (FNB) will soon begin work on an 11th edition of the RDAs, the edition that will help to guide the practice of nutrition into the 21st century. How should the RDAs be defined for this new era? Should they retain their current focus, or is a new concept needed to reflect continuing progress in nutrition science? Should prevention of chronic diseases be considered in the development of new allowances? How should the needs of nutritionally vulnerable segments of the population, such as smokers and the elderly, be taken into account? Should the process of developing new RDAs be made more open and more "scientifically democratic''? Can efforts be made to ensure consistency between the RDAs and other recommendations? All of these questions were considered at a workshop on future recommended dietary allowances held at Rutgers University on April 13, 1993. The workshop participants discussed many aspects of the RDA concept and the process by which RDAs are developed and updated. Their strongest focus, however, was on the crucial question of whether concepts of chronic disease prevention