Ageing, vegetarianism and digestive diseases are liable to generate vitamin B12 deficiencies, which must be compensated for through the diet.The same goes for some types of cancer.
The anti-anaemic virtues of veal liver were discovered in 1925. At the time, an extrinsic dietary factor was identified, which was not isolated until the middle of the century, when it was given the name vitamin B12. It is the only vitamin that incorporates a mineral (cobalt) in its composition.
Vitamin B12 is involved in many essential biochemical reactions as a coenzyme and plays a primary role in the synthesis of proteins and the production of red cells.
Vitamin B12 is only found in animal products (liver, kidneys, fish, meat). Vegetables do not contain any vitamin B12.