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difference between these two DRIs. The EAR represents the median nutrient requirement of a given life stage and gender group, and by definition, an intake at the level of the EAR will be inadequate for half the group. In contrast, the AI represents an intake (not a requirement) that is likely to exceed the actual (but unknown) requirements of almost all healthy individuals in a life stage and gender group. In this respect it is analogous to the RDA; however, because of the nature of the data used to establish AIs, they may often be higher than the RDA would be if appropriate data were available to calculate one.

The approach discussed previously to assess nutrient adequacy compares an individual's observed intake to the EAR, and considers variability in both intakes and requirements when determining how confident one can be in concluding that an individual's intake is adequate. In other words, intakes are compared to the median requirement. In the case of the AI, however, intakes are compared to an intake value in excess of the median requirement, perhaps by a very large margin. Thus, when intakes are compared to the AI, all one can truly conclude is whether intake is above the AI or not. Although an intake that is significantly above the AI is certainly adequate, intakes below the AI are also likely to be adequate for a considerable proportion of individuals. Thus, great caution must be exercised when interpreting intakes relative to AIs.

What conclusions can be drawn about individual intakes for nutrients with AIs?

First, if an individual's usual intake exceeds the AI, it can be concluded that their diet was almost certainly adequate. However, if their usual intake falls below the AI, no quantitative estimate can be provided of the likelihood of nutrient inadequacy.

Risk of inadequacy increases at some point below the AI. If the usual nutrient intake from all sources was zero, the risk of inadequacy would be virtually 100 percent. However, because the point where risk increases cannot be determined, quantitative estimates of risk cannot be made.

Even if the observed intake is above the AI, it should not be assumed that usual intake is above the AI unless a large number of days of intake data were collected. As discussed in the previous sec-

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