Vitamin K2 (menaquinone) Supplementation and its Benefits in Cardiovascular Disease, Osteoporosis, and Cancer

Vitamin K is known to play an essential role in the coagulation cascade; however, a growing body of research has found that a subtype of this vitamin, vitamin K2 (menaquinone) may have a beneficial effect in osteoporosis, cardiovascular disease, and cancer. This purpose of this article is to provide a comprehensive review of recent literature regarding menaquinone and its role in human health. This review discusses the physiology of menaquinone, its clinical benefits in cardiovascular disease, osteoporosis, and cancer, and how it may interact with certain medications. The authors conclude that menaquinone supplementation has been shown to improve carboxylation of osteocalcin and matrix-Gla protein to their active forms, two proteins that possess important roles in calcium distribution. In the setting of cardiovascular disease, menaquinone intake has been shown to lower the risk of coronary calcification and coronary heart disease, and a randomized controlled trial has demonstrated that it can reduce arterial stiffness. In osteoporosis, menaquinone has been shown by numerous randomized controlled trials to decrease the rate of bone loss at the lumbar spine and forearm and reduce the risk of fracture. In cancer, menaquinone intake has been shown to reduce overall incidence and mortality; clinical trials have suggested that it may have a role in reducing recurrence and death from hepatocellular carcinoma. However, in all clinical settings, more large randomized controlled trials are needed to definitively determine the clinical benefits of menaquinone supplementation, as many studies have failed to show any significant benefit. Lastly, more research is needed to determine how menaquinone supplementation interacts with medications such as warfarin, bile-acid sequestrants, orlistat, mineral oil and CYP3A4 substrates.