Nutritional yeast is available powdered and in larger flakes, which resemble yellow
fish food. Its most popular use is as a topping for
popcorn. It is considered a source of valuable
B vitamins (especially
vitamin B12) for
vegans, but there is controversy as to whether any brand of nutritional yeast other than Red Star T-6635 (which is fortified) actually has significant quantities of B12 in it.