Morristown, NJ – 17 July 2007 – PL Thomas announced today a new paper published in Thrombosis and Haemostasis (2007 Jul;98(1):120-5) that discusses the historic understanding of vitamin K and coagulation, as well as its newly recognized roles in bone and CV health. However, in healthy individuals, substantial fractions of the K-dependent proteins necessary for bone and CV health are not fully activated, indicating subclinical vitamin K deficiency.
According to Leon Schurgers, Ph.D., one of the authors of the paper: "Since vitamin K was discovered, we have understood its role in providing the liver's needs for proper coagulation. It is only in the last 10 years or so that we have recognized K's role activating proteins responsible for calcium utilization in the bones – and only in the past 5 years has its role in inhibiting arterial calcification been understood."
The recommended intakes of vitamin K today are based solely on coagulation. However, vitamin K is also necessary for the activation of osteocalcin, a protein necessary to transport calcium from the blood to form healthy bone matrix, and also for the activation of matrix GLA protein (MGP), the most potent inhibitor of vascular calcification known. In healthy populations, including both children and adults, the majority of individuals are sub-clinically deficient.
It is important to note that poor vitamin K status is a significant risk factor for bone loss and also for arterial calcification. In population studies of vitamin K, consumption has been linked to reduced risk of fracture and improved bone strength, and dramatic reductions in arterial calcification. There are two forms of vitamin K. K1, found in leafy green vegetables which is primarily used by the liver, and K2 (menaquinones) which are found in fermented foods such as cheese and the Japanese soy food natto, which are used also outside of the liver.
Several clinical studies have shown benefits for K1 and synthetic vitamin K2 as menaquinone-4 (MK-4), however this has only been reported at pharmacological doses ranging between 1 and 45 milligrams per day. Natural vitamin K2 as Mk-7, due to its longer half-life in the blood and bioactivity, is expected to be beneficial at nutritional levels; i.e., within recommended intake. In fact, the Rotterdam study with 4,800 participants show 50% less arterial calcification over a 10 year period at just 45mcg natural vitamin K2 consumption, with a commensurate reduction overall mortality.
Recent research has shown that the blood-thinning medication coumarin / warfarin, actually induces calcification by inhibiting vitamin K! Two human studies have published this finding, with one study showing a doubling of calcification in just 3 years time with warfarin administration. A recent animal study actually showed the reduction of preformed calcifications with vitamin K2 supplementation.
"It is likely that within 10 years the medical community will no longer use warfarin due to its unintended side effects," said Schurgers. "Until new medications are commercialized to replace warfarin with the vitamin K inhibition, we recommend supplementation with vitamin K2 under the care of a physician to help stabilize anticoagulation and protect vascular health."
An evaluation of the different types of supplemental vitamin K, taking into consideration dose, efficacy and safety, led the authors to conclude that due to its bioactivity and long half-life in the blood, natural vitamin K2 as menaquinone-7 (Mk-7) is the obvious choice for enrichment of dietary supplements and functional foods.
The paper can be found at: