Vitamin B12 is the most complex vitamin (from a chemical point of view); it contains cobalt, which is essential for its activity. Also known as cyanocobalamin, it plays a part in the proper functioning of the body, and our bodies require it every day. Although we only need it in small amounts, its importance for red blood cell production and metabolism is enormous. Various studies suggest that it has a beneficial effect on our mood and memory, and supports brain function. Vitamin B12 is necessary for maintaining the proper functioning of the nervous system and the metabolism of proteins, carbohydrates and fats. Unlike other vitamins, B12 is synthesised in nature only by bacteria found in the digestive systems of animals. We therefore obtain it mainly from animal products, such as meat and dairy products. Its uniqueness also lies in its ability to be stored in the liver for many years, but a deficiency poses a risk not only to vegans and older people. A B12 deficiency does not manifest itself immediately (it can take up to a year). Fatigue is