Though naturally present in a wide range of foods, such as eggs, cheese, and wheat germ, in the industrial realm riboflavin is produced via biosynthesis using yeast or other fermenting organisms. This manufactured riboflavin is then often used as a yellow coloring agent or for vitamin fortification of various foods. The vitamin is difficult, however, to integrate into many food items because it is insoluble in water. Therefore, a more costly water-soluble derivative, riboflavin-5'-phosphate, is often utilized instead. When ingested, this chemically prepared substance converts to free riboflavin.