Dietary Reference Intake is a set of guidelines set up in 1997 to give more detailed guidance than the RDA system which preceeded it. It was a collaboration between the USA and Canada.
It dropped the name RDA in favour of Dietary Reference Intakes (DRIs)
It added three new categories:
- Adequate intake (AI), where no RDA has been established
- Estimated safe and adequate daily dietary intake (ESADDI), expected to satisfy the needs of 50% of the people in that age group)
- Tolerable upper intake levels (UL), to caution against excessive intake of nutrients (like vitamin D) - that can be harmful in large amounts.
