CommentarySelenium is a source of aliment and ailment: Do we need more?

•Selenium supplementation is associated with beneficial and detrimental effects.•A clear relationship between DRVs, Se adequacy and optimum selenoprotein activity is needed.•Limitations exist for the use of surrogate markers to determine Se status.•A thorough evaluation of risks and benefits of Se supplementation is required.

BackgroundAlthough the prevalence of Selenium (Se) deficiency is unknown, there is an anxiety that most Europeans may be deficient in this micronutrient because data show that recommended daily intakes are not achieved. Some countries have implemented an agricultural fertilization program to raise cereal selenium concentrations, thereby boosting dietary intakes. However, the relationships between dietary reference values (DRVs), Se adequacy and optimum selenoprotein activity are unknown, while the functional sequelae of inadequate Se supply remain uncharacterized.Scope and approachThis commentary examines the benefits and disbenefits associated with Se supplementation. It highlights the inadequacy of currently used surrogate markers of Se status and an absence of clinical data to support stated benefits. The aim is therefore to stimulate debate about whether we really need more than the variable amounts we already consume.