Dietary reference intake (DRI) is a set of guidelines that the National Academy of Sciences, Institute of Medicine created in the 1990s for the United States government. These guidelines incorporate:
- Recommended dietary allowance (RDA) or an adequate intake (AI)
- Tolerable upper intake level (UL)
RDAs and AIs tell you the amount of that nutrient you should try to get each day. These values are based on scientific evidence. The amount of evidence will determine whether an RDA or an AI is given for a specific nutrient.
RDA is the average daily dietary intake level that meets the nutrient requirements of nearly all healthy people in a specific life stage and gender group. The RDA is based on the estimated average requirement (EAR), which is calculated from scientific evidence.
When there is not enough scientific evidence about a specific nutrient to calculate an EAR (and therefore an RDA), an AI is estimated instead. The AI for children and adults is expected to meet or exceed the nutrient needs of all members of a specific healthy population.
The AI is based on the scientific research available. But it is an indication that more research is needed to determine, with some degree of confidence, the necessary amount of a specific nutrient. When more research is done, it should be possible to replace AI estimates with RDAs.
UL is the highest level of daily nutrient intake that is likely to pose no risks of adverse health effects in almost all people in the specified life stage group. The UL is not a recommended level of intake. There is no established benefit for healthy people if they consume a nutrient in amounts above the RDA or AI.