Vitamin K May Lower Risk of Prostate Cancer

HEIDELBERG, Germany—Results from a recent cohort study conducted at the German Cancer Research Center, Heidelberg, suggest vitamin K many have an inverse association with prostate cancer (Am J Clin Nutr. 2008;87:985-92). Researchers estimated the dietary intake of phylloquinone (vitamin K1) and menaquinones (vitamin K2) in 11,319 men. During a mean follow-up time of 8.6 years, 268 incident cases of prostate cancer, including 113 advanced cases, were identified. There was a nonsignificant inverse association between prostate cancer incidence and total vitamin K2 intake; the association was stronger for advanced prostate cancer. Vitamin K2 from dairy products had a stronger inverse association with advanced prostate cancer than vitamin K2 from meat, while vitamin K1 intake was unrelated to prostate cancer rates.

Cees Vermeer, Ph.D., a leading vitamin K researcher at the University of Maastricht, who was not affiliated with the study, said the results help shed more light on the role of vitamin K in human health. “In the highest quartile, the relative risk (according to some advanced models) was 0.33 and even 0.29, which means a risk reduction between 67 and 71 percent,” he said. “The calculated intake in the highest quartile was 46 µg of long-chain menaquinones per day. What I appreciate most of all is that this paper comes from another group than the Maastricht one. Finally, we get support from a different angle. And, although I would have craved to be a co-author in this paper, I think it is better that also others sing the love song of MK-7.”