New research has concluded vitamin K2 consumption can aid recovery from hip fractures as well as benefiting osteoporosis

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 is 55mcg 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. In France the limit is 65mcg per day for both men and 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, not absorption, of over 300 mcg per day would be helpful to reduce the incidence of hip fracture," the researchers concluded.
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 prominent 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."
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 role 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 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 recent headline in the November 2007 issue of Mayo Clinic Health Letter “Vitamin K linked to bone strength”.

Low plasma Vitamin K1 is associated with high incidence of vertebral fracture in Japanese women.

Scientists at Kobe Pharmaceutical University in Japan note it has been reported that vitamin K supplementation effectively prevents fractures and maintains bone mineral density in osteoporosis. The objectives were to evaluate the association between plasma K1 or K2 as MK-4 and MK-7 concentration and bone health or fracture in Japanese women. A total of 379 healthy women aged 30-88 years (average age of 63) were consecutively enrolled. Plasma K1, MK-4, MK-7, BMD (bone mineral density) and incidence of vertebral fractures of the spine were evaluated. A low level of Vitamin K1was independently correlated with vertebral fracture incidence. When subjects were divided into low and high K1 groups by plasma K1 concentration, the incidence of vertebral fracture in the low K1 group (14.4%) was significantly higher than that in the high K1 group (4.2%),. Those with a low level of Vitamin K1 had a 358% increased risk of fracturing their spine and this is independent of osteoporosis. The study is published online ahead of print in the Journal of Bone and Mineral Metabolism.

Vitamin K2 linked to lower prostate cancer risk

An increased intake of vitamin K2 may reduce the risk of prostate cancer by 35 % according to results from the EPIC Study (European Prospective Investigation into Cancer and Nutrition). The potential benefits of K2 were even more pronounced for advanced prostate cancer, while vitamin K1 intake did not offer any prostate benefits, report the researchers from the German Cancer Research Centre in Heidelberg. The findings are based on data from the 11,319 men taking part in the EPIC Heidelberg cohort.
The study has been welcomed by leading vitamin K researcher Cees Vermeer, PhD, from the University of Maastricht, who stated in an interview that the study was "high quality." "The anti-tumor effect of K2 vitamins has been suggested in several other papers”
Scientists from the Division of Cancer Epidemiology at the German Cancer Research Centre state that epidemiologic studies of dietary vitamin K intakes have not been conducted in relation to prostate cancer risk. In the new study a food frequency questionnaire was used to assess habitual dietary intakes at the start of the study, with vitamin K intakes divided into vitamin K1 and vitamin K2 and total and advanced prostate cancer in the Heidelberg cohort of the Epic Study. An increased intake of all Menaquinone forms of Vitamin K2 was associated with a 35 per cent reduction in risk of developing prostate cancer. Furthermore, a strong association was documented when they considered only advanced prostate cancer, with increased intake of Vitamin K2 linked to a 63 % reduction in risk.
Dr. Vermeer states "I am highly pleased by this paper, which underpins the (widely underestimated) importance of long chain Menaquinone for disease prevention".
"It also supports my opinion that intake of vitamin K2 supplements may have a significant contribution to public health." The results of this study are published in the April 2008 issue of the American Journal of Clinical Nutrition.