Obtaining recommended intakes from unfortified foodstuffs has the advantage of providing intakes of other beneficial nutrients and of food components for which RDAs and AIs may not be determined. Another advantage is the potential enhancement of nutrient utilization through simultaneous interactions with other nutrients. It is recognized, however, that the low energy intakes reported in recent national surveys may mean that it would be unusual to see changes in food habits to the extent necessary to maintain intakes by all individuals at levels recommended in this report. Eating fortified food products represents one method by which individuals can increase or maintain intakes without major changes in food habits. For some individuals at higher risk, use of nutrient supplements may be desirable in order to meet reference intakes.
It is not the function of this report (see Appendix A, Origin and Framework of the Development of Dietary Reference Intakes) to address in detail the applications of the DRIs, including considerations necessary for the assessment of adequacy of intakes of various population groups and for planning for intakes of populations or for groups with special needs. However, some uses for the different types of DRIs are described briefly in Chapter 13. A subsequent report is expected to focus on the uses of DRIs in various settings.
Because of the difference in the bioavailability of food folate and the monoglutamate form of folate, it is recommended that both food folate and folic acid be included in tables of food composition and in reports of intake. That is, the content or intake of naturally occurring food folate should be reported separately from that of folate provided by fortified foods and supplements.
Four major types of information gaps were noted: (1) a dearth of studies designed specifically to estimate average requirements; (2) a nearly complete lack of usable data on the nutrient needs of infants, children, and adolescents; (3) a lack of appropriately designed studies to determine the role of selected B vitamins and choline in reducing the risk of certain chronic diseases; and (4) a lack of studies designed to detect adverse effects of chronic high intakes of some B vitamins.