Increased intakes of vitamin K2 decreases the risk of coronary heart disease in postmenopausal women
For every 10 microgram increase in the amount of Vitamin K2 consumed, researchers from the Netherlands report a 9 % reduction in the risk of developing coronary heart disease (CHD). The effects were mostly confined to the higher forms of vitamin K2, namely Menaquinone 7 to 9. “Our findings may have important practical implications on CVD prevention, it is important to mention that in order to increase the intake of vitamin K2, increasing the portion vitamin K2 rich foods in daily life might not be a good idea,” wrote lead author Gerrie-Cor Gast from the Julius Center for Health Sciences and Primary Care at the University Medical Center Utrecht. “Vitamin K2 might be, for instance more relevant in the form of a supplement or in low-fat dairy.”
Lead researcher Ms Gast and her co-workers evaluated data from the Prospect-EPIC cohort, consisting of 16,057 post-menopausal women, aged between 49 and 70. None of the women had cardiovascular disease at the start of the study. Dietary intakes were assessed using food frequency questions (FFQs), and participants were followed for over eight years. At the end of the study, the researchers observed an association between a higher consumption of natural vitamin K2, particularly menaquinone-7, -8, and -9 and a significantly reduced prevalence of CHD. Consumption of vitamin K1 had no effect on vascular health, said the researchers (however, we know this form builds bone effectively; Jerry Hickey, R.Ph.).
The reason behind the different effects of K1 and K2 may be due to the different distribution of each in the body, said the researchers. K1 is primarily taken-up by the liver and then cleared from circulation, while K2 is the major form of vitamin K transported also to extra-hepatic tissues, such as vessel wall and bones-tissue.
“Of the subtypes of vitamin K2, it appeared that particularly MK-7, MK-8 and MK-9 affected the risk of CHD,” said the researchers. “A stronger effect of the longer subtypes could be due to a slower hepatic clearance of these subtypes, making them longer available for carboxylation reactions.”
Commenting on the research, Dr Leon Schurgers from the University of Maastricht said: “This study confirms our findings in the Rotterdam study, showing that increased vitamin K2 intake strongly reduces the risk of coronary heart disease.” Dr Schurgers, who was not involved with the new study, added: “Also this study showed that the reduction in CHD was tied to the longer-chain menaquinones 7, 8, and 9 - the menaquinones found most abundantly in fermented cheese. As the Western diet is likely deficient in K, supplementation or enrichment of long chain menaquinones is an obvious choice.” The study is published online ahead of print in the January 28th, 2009 edition of the journal Nutrition, Metabolism and Cardiovascular Diseases.