Promotes Healthy Brain Cells: Vitamin B12 Is A Water-Soluble Vitamin With A Key Role In The Normal Functioning Of The Brain And Nervous System, And In The Formation Of Blood. It Is One Of The Eight B Vitamins Vitamin B-12 Is An Essential Water-Soluble Vitamin With A Key Role In The Normal Functioning Of The Brain, Nervous System, And Blood Formation It Is Involved In Cellular Metabolism, Dna Synthesis, And Metabolism Of Protein And Fat