Scientific Opinion on Dietary Reference Values for selenium
Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) derived Dietary Reference Values (DRVs) for selenium. The levelling off of plasma selenoprotein P (SEPP1) concentration was considered indicative of an adequate supply of selenium to all tissues and to reflect saturation of the functional selenium body pool, ensuring that selenium requirement is met. This criterion was used for establishing DRVs for selenium in adults. Evidence from human studies on the relationship between selenium intake and plasma SEPP1 concentration was reviewed. Given the uncertainties in available data on this relationship, they were considered insufficient to derive an Average Requirement. An Adequate Intake (AI) of 70 µg/day for adults was set. A review of observational studies and randomised controlled trials that investigated the relationship between selenium and health outcomes did not provide evidence for additional benefits associated with selenium intake beyond that required for the levelling off of SEPP1. No specific indicators of selenium requirements were available for infants, children or adolescents. For infants aged 7–11 months, an AI of 15 µg/day was derived by extrapolating upwards from the estimated selenium intake with breast milk of younger exclusively breast-fed infants, taking into account differences in reference body weights. For children and adolescents, the AIs for selenium were extrapolated from the AI for adults by isometric scaling and application of a growth factor. AIs range from 15 µg/day for children aged one to three years to 70 µg/day for adolescents aged 15–17 years. Considering that adaptive changes in the metabolism of selenium occur during pregnancy, the AI set for adult women applies to pregnancy. For lactating women, an additional selenium intake of 15 µg/day was estimated to cover the amount of selenium secreted in breast milk, and an AI of 85 µg/day was set.