Vitamin B12 is an important nutrient.
Food fortification . It may be a purely commercial choice to provide extra nutrients in a food , while other times it is a public health policy which aims to reduce the number of people with dietary deficiencies within a population . Vitamin B12 , also called cobalamin , is a water-soluble vitamin that has a key role in the normal functioning of the brain and nervous system , and the formation of red blood cells . It is one of eight B vitamins . Some substantial sources of B12 include animal products ( shellfish , meat ) , fortified food products , and dietary supplements .