what is b12 vitamin
Background. Vitamin B12 is an essential water-soluble vitamin that is commonly found in a variety of foods, such as fish, shellfish, meat, eggs, and dairy products. Vitamin B12 is frequently used in combination with other B vitamins in a vitamin B complex formulation.ackground. Vitamin B12 is an essential water-soluble vitamin that is commonly found in a variety of foods, such as fish, shellfish, meat, eggs, and dairy products. Vitamin B12 is frequently used in combination with other B vitamins in a vitamin B complex formulation.