from supplements or food fortificants only, the UL is based on nutrient intake from those sources only, not on total intake. The UL applies to chronic daily use.
For some nutrients, there may be insufficient data on which to develop a UL. This does not mean that there is no potential for adverse effects resulting from high intake. When data about adverse effects are extremely limited, extra caution may be warranted.
Although the RDA and AI are used for the same purpose—setting goals for intake by individuals—the RDA differs from the AI. Intake of the RDA for a nutrient is expected to meet the needs of 97 to 98 percent of the individuals in a life stage and gender group. If the EAR is not known, as is the case when an AI is set, it is not known what percentage of individuals are covered by the AI. The AI for a nutrient is expected to exceed the average requirement for that nutrient, and it should cover the needs of more than 98 percent of the individuals, but it might cover the needs of far fewer (see Figure S-1). The degree to which an AI exceeds the average requirement is likely to differ among nutrients and population groups.
For people with diseases that increase requirements or who have other special health needs, the RDA and AI may each serve as the basis for adjusting individual recommendations; qualified health professionals should adapt the recommended intake to cover higher or lower needs.
In this report, AIs rather than EARs and RDAs are being proposed for all nutrients for infants to age 1 year, and for calcium, vitamin D, and fluoride for all life stages. The method used to derive the AI differs for each nutrient and for infants as follows.
The AI is the intake by healthy breastfed infants as obtained from average human milk nutrient composition and average milk volume. Since infants self-regulate milk intake from the breast, it is presumed that larger infants, who may require more milk than the average population intake, will achieve this by increasing milk intake volume.