Science and Education Publishing Journal of Food and Nutrition Research 2333-1240 4 5 2016 6 17 Changes on Levels of Essential Trace Elements in Selenium Naturally Enriched Milk 303 308 EN Amelia González-Arrojo Ana Soldado Fernando Vicente M Luisa Fernández Sánchez Alfredo Sanz-Medel Begoña de la Roza-Delgado Department of Nutrition, Grasslands and Forages, Regional Institute for Research and Agro-Food Development, SERIDA, Villaviciosa, Spain JFNR2016456 10.12691/jfnr-4-5-6 2016 2 22 2016 4 6 2016 6 15 Selenium (Se) enrichment improves milk functional nutrient content enhancing its nutritive value and providing health benefits. This Se enriched milk can be considered as 'nutraceutical' or 'functional food'. However, this benefit should not affect negatively other milk properties, such as its trace element contents. Holstein-Friesian cows diets were supplemented with increasing Se dosages in order to obtain on-farm Se enriched milk, and trace metals content including Co, Cu, I, Se and Zn were determined in these milk samples. Our results showed that Se milk supplementation did not affect negatively other trace element levels in milk, obtaining a functional food designed to allow consumers to drink enriched milk close to their natural state. No effect was detected on Co, I and Zn at any Se supplementation dosages. However, Cu level decreased when Se concentration in milk was higher than 100 ng/g.