Creamy or chunky, with chocolate or jelly, peanut butter has been an American staple for generations. National Peanut Butter Day is January 24th. Peanut butter is a good source of vitamin E, B6, niacin, calcium, potassium and iron, is packed with protein and is rich in healthy monounsaturated fat. Spreading peanut butter on bread from a jar of peanut butter.