Vitamin B12 is also called cobalamin.
The human body needs an intrinsic factor, which is produced in the stomach, to absorb vitamin B12 in the small intestine.
Vitamin B12 can be stored in the body especially in the liver and a full store usually contains enough vitamin B12 for several years.
The only sources for vitamin B12 are animal products: milk, cheese, yoghurt, eggs, meat and fish.
Vegans must supplement this vitamin!!
The daily recommended dose for women and men are 3 μg.