Vitamin B12 (cobalamin) is one of the 13 vitamins essential to human health and life. It is crucial for the construction of DNA, 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. A B12 deficiency can result in symptoms ranging from severe anemia requiring blood transfusions, fatigue, muscle soreness, memory loss, and behavioral changes to serious and permanent nerve damage. B12 is found naturally in animal foods or is received through supplements, and must follow a complex pathway of several steps for proper absorption. Monobind's assay measures total B12 in serum.