A new study published in the April 15 issue of Blood, the official journal of the American Society of Hematology, reveals greater benefits of vitamin K2 over K1 in promoting bone and cardiovascular health. The four-part human study demonstrated that vitamin K2 as menaquinone-7 (or MK-7) was superior to vitamin K1 in several important areas, including better absorption, much longer bioavailability and higher efficacy levels in the body.
“This is the first human study using natural vitamin K2 as a dietary supplement. It shows that vitamin K2 as MK-7 is clearly the most beneficial and potent K-vitamin that one can take,” said lead researcher Leon Schurgers, Ph.D., Cardiovascular Research Institute, Maastricht University, Maastricht, the Netherlands. “Large scale human studies have shown that eating foods rich in vitamin K2 significantly promotes bone health, reduces risk of bone injury, and significantly promotes cardiovascular health.”
The study showed that MK-7 was absorbed into human blood as quickly as K1, but with a 1.5 fold better absorption and also remained at potent levels for a significantly longer period of time. MK-7 also more effectively promoted and activated markers of bone building, and demonstrated a dramatic advantage over K1 in counteracting the vitamin K antagonist effect of the commonly prescribed blood-thinning medication, warfarin. Warfarin has been shown to increase calcification in the arteries, a known independent risk factor for cardiovascular disease.
The benefits of vitamin K for cardiovascular disease are supported by the findings of a Dutch study called the “Rotterdam study” (Geleijnse et al) examining the benefits of dietary Vitamin K and its role in preventing coronary heart disease (CHD) in 2004. This study involved over 4,800 people over a 10-year period and revealed that increased dietary intake of vitamin K2 significantly reduced the risk of CHD mortality by 50% as compared to low dietary vitamin K2 intake. In that study, vitamin K1 had no effect at all.
The primary reason for MK-7’s superiority appears to be its very long three-day half-life in the blood, compared to 1 to 2 hours for K1, which results in more-stable blood levels and significantly greater accumulation of vitamin K (MK-7) in the blood. In addition, the study reveals MK-7 as having better blood coagulation cofactor activity and dramatically higher bioactivity.
Vitamin K is an essential micronutrient and necessary in our human diet to activate vitamin K–dependent proteins involved in the utilization of calcium—both for building strong bones and inhibiting calcium accumulation in the arteries. Vitamin K is also necessary for producing blood coagulation. Accumulating scientific evidence suggests that optimal bone and vascular health requires a relatively high intake of vitamin K, especially K2, more than previously thought to be satisfactory in a typical healthy diet.
Until recently, vitamin K1 has been the main variety of the vitamin K family that has been used in commercial supplements and is the most common variety contained in food groups. Recent health claims in scientific literature related to natto (a traditional Japanese food made from fermented soybeans) consumption has given rise to an increasing interest in MK-7, a natto extract, as a potential improvement over vitamin K1 in supplementing a healthy diet.
