Sometimes called Lipotropic B12, (methionine, inositol, choline, methyl cobalamin) helps with the breakdown of fat during metabolism in the body. Your body uses methionine to make proteins and other amino acids which help in weight loss, sugar metabolism, and normal function of your immune system. Choline works to prevent accumulation of fat in the liver and vascular system. Inositol improves insulin sensitivity, which is helpful in muscle building and fat loss. A lack of vitamin B12 can cause memory loss, dementia and numbness in the arms and legs.