Estimated Average Requirement (EAR) is the average daily nutrient intake level that is estimated to meet the requirements of half - 50% - of the healthy individuals in a particular life stage and gender group.
Because the needs of the other half of the population will not be met by this amount, the EAR is increased by about 20% to arrive at the RDA.
Before setting the EAR, a specific criterion of adequacy is selected, based on a careful review of the literature. When selecting the criterion, reduction of disease risk is considered along with many other health parameters.
Antioxidants - substances that may prevent or delay some types of cell damage. Examples of antioxidants include beta-carotene, lutein, lycopene, selenium, vitamins A, C and E.
Vegetables and fruits are rich sources of antioxidants. There is good evidence that eating a diet with lots of vegetables and fruits is healthy and lowers risks of certain diseases. But it isn't clear whether this is because of the antioxidants, something else in the foods, or other factors. Most clinical studies of antioxidant supplements have not found them to provide substantial health benefits.