It helps in the formation of red blood cells, production of energy and in the maintenance of the central nervous system. B12 also supports the normal brain function. Vegetarians should take special care to get adequate B vitamins because dietary sources of B12 are mostly found in foods of animal origin. Many people over age 50 lose the ability to absorb vitamin B12 from foods. Moreover people who have had gastrointestinal surgery or have digestive disorders may not absorb vitamin B12 adequately.