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Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification
and dietary supplement databases; changes in nutrition labeling and consumer research on its use.
RESEARCH IN SUPPORT OF DETERMINING NUTRIENT REQUIREMENTS
The DRI reports identified a set of research priorities for each nutrient (IOM, 1997, 1998, 2000b, 2001, 2002a). One priority was the need to establish EARs for nutrients where data were insufficient to set them at the time (e.g., vitamin D) (IOM, 1997). EARs have multiple uses. As mentioned in Chapter 6, without an EAR it is not possible to estimate the population prevalence of inadequacy for a nutrient following the approach used in the DRI assessment report (IOM, 2000a). The committee recommends that the U.S. Department of Health and Human Services (DHHS), the U.S. Department of Agriculture (USDA), and Health Canada promote and support basic research that will lead to the development of EARs that were not established by the DRI panels, especially for those nutrients that are deemed important for public health or for special populations. Nutrients currently without EARs include vitamin D, vitamin K, pantothenic acid, biotin, choline, calcium, chromium, fluoride, manganese, total fiber, linoleic acid, and α-linolenic acid.
The research needs are described in detail in the DRI volumes for each nutrient. In general, these research needs include studies to provide the basic data to construct risk and benefit curves across graded exposures to food- and supplement-based intake of a nutrient while monitoring a combination of response indices. They also point to the need for subpopulation-specific information even for those nutrients with EARs. For example, for vitamin C, vitamin, E, selenium, and β-carotene and other carotenoids, useful data are seriously lacking for setting requirements for adolescents, pregnant and lactating women, and the elderly (IOM, 2000b).
BIOLOGICAL ENDPOINTS UNDERLYING THE TOLERABLE UPPER INTAKE LEVELS AND INFORMATION ON ADVERSE EFFECTS
For many nutrients the DRI panels were unable to set ULs because data were not available on adverse effects that had been associated with high intakes of the nutrient from food sources (see Appendix C). Some nutrients clearly had adverse effects associated with doses of the nutrient either consumed as a dietary supplement or for treatment purposes, such as the development of neuropathy with high