data on the nutrient needs of infants, children, adolescents, and pregnant and lactating women; (3) a lack of definitive studies to determine the role of these nutrients in lowering the risk of certain chronic diseases; (4) a lack of validated biomarkers to evaluate oxidative stress and the relationship between antioxidant intake and health and disease; and (5) a lack of studies designed to detect adverse effects of chronic high intakes of these nutrients.
Highest priority is thus given to research that has potential to prevent or retard human disease processes and to prevent deficiencies with functional consequences as follows:
Studies to provide the basic data for constructing risk curves and benefit curves across the exposures to dietary and supplemental intakes of vitamin C, vitamin E, selenium, and β-carotene and other carotenoids. Studies should be designed to determine the relationship of nutrient intakes to validated biomarkers of oxidative stress. These studies should be followed by nested case-control studies to determine the relationship of the biomarkers of oxidative stress to chronic disease. Finally, full-scale intervention trials should be done to establish the preventive potential of a nutrient for chronic disease.
Investigations of gender specificity of the metabolism and requirements for vitamin C, vitamin E, selenium, and β-carotene and other carotenoids.
Studies to validate methods and possible models for estimating Dietary Reference Intakes (DRIs) in the absence of data for some life stage groups, such as children, pregnant and lactating women, and older adults.
Research to determine the interactions and possible synergisms of vitamin C, vitamin E, selenium, and β-carotene with each other, with other nutrients and food components, and with endogenous antioxidants. Multifactorial studies are needed to demonstrate in vivo actions as well as synergisms that have been shown to occur in vitro.
Studies to develop economical, sensitive, and specific methods to assess the associations of vitamin C, vitamin E, selenium, and β -carotene and other carotenoids with the causation, prevalence, prevention, and treatment of specific viral or other infections.
Investigations of the magnitude and role of genetic polymorphisms in the mechanisms of actions of vitamin C, vitamin E, selenium, and β-carotene and other carotenoids.