Vitamin K1 Shown to Benefit Heart Health - by Nancy Hirsch, CN

A study in the June, 2009 issue of American Journal of Clinical Nutrition states that supplementing with vitamin K1, also known as phylloquinone, may slow hardening of the arteries in people already suffering from the condition. "Vitamin K1 reduced the progression of existing coronary artery calcification (CAC) in asymptomatic older men and women when taken with recommended amounts of calcium and vitamin D," wrote the researchers.

500 mcg per day of vitamin K1 slowed coronary artery calcification in men and women independently of changes in levels of a protein called matrix Gla protein (MGP). The reason this is significant is because MGP is the protein that regulates calcium crystal formation in the circulatory system, and vitamin K1 is required to activate this protein. "MGP is the most powerful inhibitor of soft tissue calcification presently known and it needs vitamin K to be active. Vessel walls have only MGP to defend themselves against calcification," said Professor Cees Vermeer, a vitamin K expert. Optimal K1 levels are needed to produce proper amounts of MGP to prevent arterial calcification.

There are two main forms of vitamin K, phylloquinone (vitamin K1) which is found mostly in dark, leafy green vegetables, and makes up about 90 percent of the vitamin K found in the typical American diet, and menaquinones (vitamin K2) which accounts for the other 10 percent. Some vitamin K1 is converted into K2 in the intestines, but we can get vitamin K2 from meat, egg yolks, and fermented foods such as ripe cheese, tempeh,  miso and natto, a fermented soy food.

This new study adds to the growing body of evidence which states that both vitamins K1 and K2, are, for different reasons, necessary for heart health.