Vitamin B12 also known as cobalamin, is a water-soluble vitamin involved in metabolism that has many health benefits. It helps in formation of red blood cells, smooth liver functioning, and also the synthesis of DNA. It has also been proven that vitamin B12 promotes healthy brain functioning and boosts overall metabolism.The Reference Daily Intake (RDI) of vitamin B12 for adults is about 2.4 micrograms. Vitamin B12 is absorbed in your stomach with the help of a protein called intrinsic factor. This substance binds to the vitamin B12 molecule and helps your blood and cells absorb it and further help with the functioning. As per a study by Complementary Therapies in Medicine, it is said that vitamin B12 supplementation, along with folic acid, improved glycemic control and insulin resistance in patients with type 2 diabetes mellitus. Take a look at 9 foods which are the highest source of Vitamin B12 and one can add them in their regular diet.