Selenium content and distribution in bovine and human milk from different regions of Poland

Human milk and bulk cow's milk samples from 3 different areas of central Poland were analyzed for their Se content. Cow's milk specimens were also analyzed for Se distribution and GSH-Px activity. Mature human milk contained 34-68% more Se than bulk cow's milk obtained from analogous areas of central Poland. Comparison of literature values suggest, that human and cow's milk from vicinity of Warsaw and Piotrków Trubunalski were Se-adequate but milk from Siedlce area was Se-deficient. Glutathione peroxidase activity accounted for 25-31% of the total peroxidase activity of cow's milk. The majority of the Se was found in the whey fraction. It was suggested that the participation of the casein fraction in total milk selenium increased faster than milk Se content. Cow's milk obtained near Warsaw had a 2-times higher concentration of Se than in milk from Siedlce but the content of this microelement in the casein fraction (pellet) was 3-times higher.