Strong Bones, Comfortable Joints
by Jerry Hickey, R.Ph.
Japanese researchers found a link between Vitamin K2 and prevention of hip fractures and also decreasing the incidence of osteoporosis, and suggested a review of the, “dietary reference value of Vitamin K from the perspective of osteoporosis would be useful.” The current Japanese reference value for Vitamin K intake is 55mcg per day for women and 65mcg per day for men. In the US and Canada it is 120mcg per day for men and 90mcg per day for women. “Since regions which consumed a lot of Vitamin K, especially Vitamin K2, showed a low incidence of hip fracture, we considered that Vitamin K intake of over 300 mcg per day would be helpful to reduce the incidence of hip fracture,” the researchers note.
Natto, a food made from fermented soy beans, was singled out as being a particularly abundant Vitamin K source. The researchers recognized that the role of Vitamin K in assisting bone health is relatively new. “Calcium, the most studied nutrient in the area of bone health, is known for its effectiveness in retarding bone loss in postmenopausal women,” they said. “Magnesium and Vitamin D play important roles in calcium and bone metabolism. Vitamin K, originally recognized as a factor required for normal blood coagulation, is beginning to receive more attention for its role in bone metabolism.” Estimates suggest that in the absence of primary prevention, the number of hip fractures worldwide will increase to approximately 2.6 million by the year 2025, and up to 4.5 million by the year 2050. Osteoporosis weakens bone strength which increases the likelihood of hip fracture, a problem that increases with age. The study is published in the current issue of the European Journal of Epidemiology. Note; a headline in the November 2007 issue of the Mayo Clinic Health Letter “Vitamin K linked to bone strength.”
The study assessed population diets in various regions of Japan as well as dietary differences, and found that those regions where certain Vitamin K2-rich fruits and vegetables were commonly consumed had reduced rates of hip fracture. “There was also a striking pattern of high intake of Vitamin K and low incidence of hip fracture in eastern areas of Japan, with the opposite pattern-a low intake of vegetables rich in Vitamin K and a high incidence of hip fracture-in western areas,” they wrote. “These findings lend support to the idea that Vitamin K is an important factor explaining regional differences in the incidence of hip fracture.”