Vitamin K is one of the vitamins that are soluble in fats. There are three forms of vitamin K (K1, K2 and K3). Probably the least known of them is vitamin K2 the source of which are, for example, fermented cabbage (sauerkraut) as well as eggs and butter - but only from grass-fed cattle and pasture-raised poultry. Indeed, vitamin K2 is very important in helping to maintain a normal condition of bones by assisting a regular transport of calcium. It is therefore advisable to use vitamin K2 in combination with the already mentioned calcium as the basic structural element of bones and teeth.