Vitamin B12 belongs to the group of B vitamins. It is water-soluble, with the trace element cobalt as its central atom. Vitamin B12 fulfils a variety of functions in the human body, especially important metabolic mechanisms. Since the vitamin can be produced exclusively by microorganisms, it is one of the vitamins most frequently supplemented. Especially with a vegetarian or vegan diet, people regularly look for an additional source of vitamin B12.