Vitamin B12 is one of the eight vitamins of the vitamin B group, and the only one that the body can store specifically. Our liver stores large quantities of the vitamin that can last months to years, to be released back to the blood when needed. Even if the stocks of the other B-vitamins are used up earlier. Compared to vitamin B12, they remain for a shorter time in our body until they are utilized or excreted. Therefore, low supply of vitamin B12 or impaired absorption in the digestive tract becomes noticeable only after a while. Vitamin B12, also known as cobalamin, has different metabolic functions. It helps to maintain the homocysteine level low, thereby protecting the heart and blood vessels. It is involved in cell division and blood formation, and is crucial for normal nerve functioning. The latter function will be explained in more detail.