observed for a large number of days and are at the RDA, or observed intakes for fewer days are well above the RDA, should one have a high level of confidence that the intake is adequate. Such considerations are not applicable in the case of energy intake, which should match energy expenditure in individuals maintaining desirable body weight.

Adequate Intakes (AIs) have been set for all nutrients discussed in this report for all life stage and gender groups, with the exception of sulfate. Equations that can be used to estimate the degree of confidence that an individual’s usual intake meets or exceeds the AI have been developed (IOM, 2000). Usual individual intakes that are equal to or above the AI can be assumed to be adequate. However, the likelihood of inadequacy of usual intakes below the AI cannot be determined. For example, an adult with a usual potassium intake of 5 g/day could be assessed as having an adequate intake since intake exceeds the AI of 4.7 g/day. However, no conclusions regarding the adequacy of an intake of 3.5 g/day (i.e., below the AI) can be made since, by definition, when an AI is set there is insufficient information about the distribution of requirements. Accordingly, whether an intake below the AI meets an individual’s requirement cannot be assessed since the requirement distribution is not known.

The Tolerable Upper Intake Level (UL) is used to examine the possibility of over-consumption of a nutrient. Equations have been developed to determine the degree of confidence that an individual’s estimated intake is actually below the UL (IOM, 2000). If an individual’s usual nutrient intake remains below the UL, there is little risk of the identified adverse effect occurring from excessive intake. At chronic intakes above the UL, the potential for risk of adverse effects increases. However, the intake at which a given individual will develop the adverse effects associated with taking large amounts of one or more nutrients is not known with certainty. In this report, a UL has been established only for sodium. However, there is no established benefit to almost all healthy individuals who chronically consume amounts of nutrients that exceed the AI; it should be noted that acute adverse effects, which should be avoided,