menaquinone

Menaquinone is the generic name for a group of compounds collectively known as vitamin K2. It is one of the three main types of vitamin K, alongside phylloquinone (vitamin K1) and menadione (vitamin K3). Menaquinones are characterized by their unsaturated isoprenyl side chains, with subtypes designated as MK-n based on the number of isoprenyl units. The most studied forms include MK-4, MK-7, and MK-9[3][4][5]. Menaquinones are produced by bacteria in the human gut and found in animal-based foods and fermented products such as natto[3][4][6]. Mechanistically, menaquinones act as cofactors for gamma-glutamyl carboxylase enzymes that activate vitamin K-dependent proteins involved in blood clotting (e.g., prothrombin) and bone metabolism (e.g., osteocalcin)[3][5]. They also play roles in preventing vascular calcification via activation of matrix Gla protein[5]. Clinical evidence supports their use for improving bone strength/reducing fracture risk in osteoporosis; they may also benefit cardiovascular health by reducing arterial calcification[1][5][6]. Additional research suggests potential benefits for diabetes management, peripheral neuropathy, cancer suppression via cell-cycle arrest/apoptosis pathways, and possibly neuroprotection[5].

Other names

vitamin K2MKmenaquinones (MK-4 through MK-13)menatetrenone (MK-4)menaquinone-7 (MK-7)vitamin K~2~