Vitamin B12 is a vitamin your body needs but cannot produce. it is used to treat vitamin B12 deficiency in people with pernicious anaemia. b12 supports the normal function of your nerve cells and is needed for red blood cell formation.  It can also bring on immediate health benefits such as Increased energy levels and concentration, it can improve metabolism and help with weight loss. B12 is known to boost immune system, help improve sleep patterns, improve hair loss conditions and much more.