Vitamin K, or anti-hemorrhagic vitamin (derived from koagulation), is a fat-soluble vitamin that occurs in two different forms: K1 (phylloquinone), of plant origin, and K2 (menaquinone), which appears to be synthesized from the gastrointestinal microbiota. Menadione (K3) is the synthetic chemical compound of vitamin K, and it is not generally used as a nutritional supplement. K avitaminosis does not usually occur for an unbalanced diet but, rather, for a gut microbiota alteration. K avitaminosis could, rather, occur in newborn babies for poor levels in mother milk, when the intestinal microbiota is still underdeveloped.
Vitamin K is necessary to synthesize vitamin K-dependent proteins that are biologically active (prothrombin, protein C, protein S, protein Z). Recent studies have highlighted Vitamin K's beneficial effect in osteoporosis and atherosclerosis, and this has triggered the development of new and specific natural ingredients. Menaquinone MK-7 is the most available and bioactive supplement form of vitamin K2. In 2008, an oil suspension of a K2-rich extract was approved as a novel food ingredient. It is obtained with the fermentation of soybean protein isolate in the presence of Bacillus subtilis natto, a Gram-positive bacterium (Mena Q7®, NatoPharma) (EFSA, 2008).
Kappa Bioscience AS, a Norwegian company, distributes a microencapsulated product containing the three essential ingredients for bone health: vitamin K2, calcium, and Vitamin D.