Labeled as Selenium Yeast, Sel-Plex is a true breakthrough in Canine nutrition. Selenium Yeast is the sole source of added selenium in all Victor dry kibble dog food formulas. It is a much more effective and safer choice than the inorganic form labeled Sodium Selenite. Selenium works with Vitamin E to become a powerful Antioxidant that works to support cellular regeneration and immune system response. The unique feature of Selenium in this Organic form can be absorbed in the blood stream and be stored in cells for use during times of stress. Sel-Plex video en Español.