Why RDAs and ULs are incompatible standards in the U-shape micronutrient model: a philosophically orientated analysis of micronutrients' standardizations.

Risk assessments of micronutrients are carried out in the customary deficiency-excess model. It is regarded as straightforward and unambiguous. Nevertheless, it is a problematic amalgamation of two different and to a certain extent contrasting perspectives on risk and science that we will criticize in this contribution. Our critique is framed in a conceptual scheme of opposing perspectives highlighted by the rival characteristics of RDAs and SULs and the role of science therein. The one part of our scheme holds the typically modern approach that centers on risks that can be scientifically assessed more or less confidently. Subsequent policies are aimed at preventing major health problems that affect the majority of the population from early on in life. The RDAs are the ideal type-case here. The other part of our scheme holds a much more postmodern approach in which health risks are explicitly recognized as "uncertain." Dealing with those risks has little to do with major health problems from early on in life. Here, we encounter the scientific quandary of disentangling complex factors and impacts that may relate to some extra quality of life later on in life. SULs are exemplarily thereof. We will show that RDAs originally spawned from the scientific aim of securing objective knowledge "to lay down the requirements of an adequate" diet. SULs, conversely, are the upshot of generating acceptable outcomes driven by ever-increasing safety requirements. This shift from securing objective knowledge to generating acceptable outcomes will be addressed in relation to precautionary culture.