Vitamin K2 promotes healthy bones
Bone is a living substance comprised of a hard outer shell and spongy inner tissue matrix. The entire skeleton is replaced approximately every seven years. This process is regulated by soluble factors and by cells (osteoblasts, cells that build up bone tissue, and osteoclasts, cells that break it down). Osteoblasts produce the vitamin K-dependent protein osteocalcin. This protein binds calcium to the bone matrix and builds healthy bones. As long as the bone-forming activity (absorption) is greater than the bone-breakdown (resorption), the process of maintaining healthy bones is kept under control.
Osteocalcin is a vitamin K-dependent protein, which means it needs natural vitamin K2 to function properly31. Thus long-term vitamin K-deficiency may lead to loss of calcium in the bone and reduced quality of bone. Populations that consume a significant amount of natural vitamin K2 have stronger, healthier bones. Unfortunately, the Western diet does not contain sufficient vitamin K2 and the majority of healthy people are therefore vitamin K2 deficient.
Maintaining healthy bones with Vitamin K2
Many studies with vitamin K have linked vitamin K consumption to bone health. A brief overview of recently published research includes the 2003 European study which revealed that vitamin K supplementation helps promote bone health and preserve bone mineral density32. A three-year follow-up European study looked at two groups of patients: a control group receiving no supplementation and a group that was given supplemental vitamin K2. This study showed very good preservation of bone strength for the entire supplementation period33.
A groundbreaking study by Kaneki in 2001 suggested that increased intake of MK-7 from natto resulted in better levels of activated osteocalcin and a reduced risk of hip fracture34. These results were confirmed in 2006 in a study by Ikeda, who found that consuming MK-7 rich natto, may help preserve bone health. This three-year study with 944 women (aged 20-79) linked intake of MK-7 to the preservation of bone mineral density35.
Most recently, a study published by Yaegashi (in the European Journal of Epidemiology (2008) showed that better vitamin K status resulted in significant protection of the hip36. In this study, both calcium, magnesium, zinc and vitamin D were shown to be important for bone health. However, natural vitamin K2 from natto was identified as the key ingredient for preserving bone health.
In a study published in the journal Blood by Schurgers et al (2007), the MK-7 containing product MenaQ7 was consistently found to be much more effective compared to vitamin K137. Subsequent comparisons to the synthetic MK-4 again demonstrated the superiority of MK-7 as MenaQ7. This is partly explained by significantly greater bioavailability and bioactivity of MK-7 compared to other sources of K vitamins.