Vitamin B12 (cobalamin) is one of the 13 vitamins our body needs for health and life. It is essential for the production of red blood cells and aids in the maintenance of a healthy nervous system. B12 deficiency damages the brain, spinal cord, peripheral nerves, and nerves of the eye. It is a crucial element in the construction of DNA. A B12 deficiency can result in symptoms ranging from severe anemia requiring blood transfusions, to serious and permanent nerve damage. B12 is found naturally in animal foods including meat, fish, shellfish, poultry, dairy products, and eggs. Vitamin B12 must follow a complex pathway of several steps for proper absorption. A roadblock in any part of this pathway can cause malabsorption and subsequent deficiency.