Vitamin B 12 is a water-soluble vitamin. It is one of the eight B-vitamins (Vitamin B-complex). It is naturally present in some foodstuffs and can also be available as artificially added to the food. It can also be available in the form of dietary supplements. Since it contains mineral cobalt, the compounds with vitamin B12 activity are also called cyanocobalamin. The human body can store vitamin B12 for up to 4 years, almost 50% of it in the liver. Excess of vitamin B 12 is excreted out of our body through urine.