Vitamin B12 is an essential water-soluble nutrient for the normal function of several body systems, including the cardiovascular, nervous, and digestive systems. It also helps support liver function and the detoxification process. A diet without adequate B12 can adversely affect the production of basic building blocks, like RNA and DNA, but also the production of red blood cells. Research shows that many people can have difficulties metabolizing and absorbing B-12, especially when digestive and/or intestinal functioning is suboptimal. For these people, intravenous therapy or intraoral liposomal delivery are the best methods for achieving rapid shifts in blood levels of this key nutrient.