Selenium is a trace mineral, and like all minerals, it is an essential nutrient that the body cannot naturally produce and must be obtained from foods or supplements. Each Selenium tablet delivers 200 mcg of Selenium as Selenium Yeast, the active form of this mineral. Selenium is a naturally occurring antioxidant that can be found in seafood, poultry, wheat, and grains. It may be difficult to obtain the required daily amount through food alone. The amount of Selenium within food varies based on where and how the food was grown, as the levels of Selenium within soil in various landscapes are not consistent. At a dose of just one tablet per day, this 100-count bottle of Selenium will last you more than three months! Additionally, these tablets are vegan friendly and free of gluten, artificial colors, flavors, soy, and dairy.