Vitamin D
Vitamin D3 naturally occurs almost exclusively in animal sources, particularly in fish, dairy products, eggs and meat. Plants, such as lichens and various fungi, contain only very small amounts of the much less effective form of vitamin D2.
Vitamin D plays a very important role in the body. It is one of the few vitamins that is not absorbed directly from food, but rather produced by skin cells from sunlight. It is not a vitamin in the traditional sense of the word, but rather a pro-hormone. Almost all body cells have special receptors for the vitamin D hormone and are dependent on an adequate supply of it.
Vitamin K2 is the most important cofactor of vitamin D in the regulation of calcium metabolism. Together, the two vitamins control bone-building as well as breaking down cells and important transport molecules that ensure the correct utilisation of calcium.
Vitamin D is still being intensively researched. New mechanisms of action of this fascinating vitamin are discovered almost every year. So far, the following statements on vitamin D have been released by the EU (EFSA):
Vitamin D contributes to:
- the normal absorption and utilisation of calcium and phosphorus
- normal blood calcium levels
- the maintenance of bones
- the maintenance of normal muscle function
- the maintenance of healthy teeth
- the normal function of the immune system
- cell division
Vitamin K contributes to:
- normal blood clotting
- the maintenance of normal bones
Vitamin K2 exists in various forms, which have different levels of effectiveness. Vitamin K2 MK-7 is considered by far the most effective form of K2 today. However, since vitamin K2 molecules occur in a variety chemical structures (the so-called cis–trans isomers of vitamin K2), there are considerable differences in efficacy even between different vitamin K2 MK-7 compounds. It is believed that only the trans forms can be utilised by the body.
