Comvita Selenium contains 50 mcg per tablet and comes in 100 and 200 tablet bottles while Comvita Selenium Ace comes in a 60 tablet bottle with 100 mcg of Selenium per tablet. The selenium in Comvita Selenium and Selenium ACE products is food form selenium, the most processable form available. Our product also carries the ‘Nutrition 21’ seal – the leading USA brand guaranteeing a safe, food-form natural product.