Vitamin K for Your Arteries?

People with large amounts of calcium in their arteries usually have more extensive atherosclerotic damage to their arteries and are at a greater risk of a heart attack. The results of a study of 600 men, 50 to 70 years old, with no symptoms of coronary artery disease, were reported at the annual meeting of the American Heart Association this past winter. Dr. Woods, who conducted the study, found that men with the most calcium in their arteries were found to be much more likely to have poor vitamin K status. Research in rats who were given warfarin, a drug that blocks the action of vitamin K, has shown that these rats develop extensive calcification of their arteries.1

Vitamin K has long been known to be necessary to produce proteins involved in the clotting of blood. However, it has more recently been shown to be necessary for bone formation. Low levels of vitamin K may increase the risk of osteoporosis. Warfarin, a.k.a. coumadin, is frequently prescribed to prevent blood clots due to valvular heart disease because it reduces the risk of blood clots that can lead to strokes. Of course many people with heart valve problems also have atherosclerosis that can lead to both heart attacks and strokes. The results of Dr. Woods? study coupled with those in animals suggest that coumadin may promote calcification of the arteries by interfering with the action of vitamin K.A recent follow-up study of nearly 10,000 adults examined back in the 1970s found that those who consumed more fruits and vegetables were 42% less likely to die of a stroke and 24% less likely to die of a heart attack than those who consumed the least amount of fruits and vegetables.2 Vitamin K comes primarily from fruits and vegetables. Of course fruits and vegetables contain fiber, other nutrients besides vitamin K, and many phytochemicals that appear to reduce the risk of many diseases common in the U.S. The Feb. 5, 2002 issue of the Annals of Internal Medicine published the results of a 12-year study of more than 42,000 men by Harvard researchers. Those men who consumed a typical Western diet high in animal products, and low in fruits, vegetables and whole grains, were 60% more likely to develop diabetes than those who consumed a more prudent diet. While it may be premature to tell patients on coumadin to stop their medication, it is certainly good advice to tell all Americans to increase their intake of vegetables, fruits and whole grains.By Dr. James J. Kenney, PhD, RD, FACN1. Intern Medicine News, Feb. 1, 20022. Clin Nutr 2002;76:03-9