Vitamin B12 is a water-soluble vitamin that is essential in the body for proper function of red blood cell production, neurological function, and DNA Synthesis. Vitamin B12 is bound to protein in food unless added to fortified foods. Food Sources of B12 Vitamin B12 is naturally found in animal products, including fish, poultry, eggs, milk, and milk products. Vitamin B12 is generally not present in plant foods, but fortified breakfast cereals are a readily available source of