Population reference intakes and micronutrient bioavailability: a European perspective.

The processes of setting population reference intakes in the European Union and elsewhere have highlighted the paucity of data for informing the assessments and the need to take the opportunity to establish transparent, physiologically based approaches to setting reference values for safe and adequate intakes, including considerations of excess exposures. The confusion arising from the European exercise contributed to a number of initiatives to rationalize approaches to setting reference levels and safe upper levels of intake. A biologically based approach to nutrient risk assessment, which has many features that could be extended advantageously to the creation of a similar approach to setting nutrient reference values, has been proposed. This approach has yet to be explored, but an additional product of the earlier confusion has been the development of proposals for the international harmonization of approaches to setting nutrient-based dietary standards that could lead to internationally agreed-upon standards for nutrient risk assessment and for setting key intake values.