Nutritional yeast is a deactivated form of yeast, often derived from the species Saccharomyces cerevisiae. It is commonly used as a dietary supplement and flavoring agent, particularly in vegan and vegetarian diets. Nutritional yeast is rich in vitamins, especially B vitamins, and is a good source of protein, making it a popular choice for those looking to enhance their nutrient intake. This yellow, flaky substance has a cheesy, nutty flavor, which makes it a favorite ingredient in various dishes, such as popcorn, pasta, and sauces. Nutritional yeast is often fortified with vitamin B12, an essential nutrient that is typically found in animal products, making it an important addition for those following plant-based diets.