Jianjun Zhang

Indiana University

PLCO (Learn more about this study)

2011-0121

Oct 6, 2011

Dietary Intake of Vitamin K and Risk of Prostate Cancer

Vitamin K has two forms that naturally occur in foods, i.e., phylloquinone (vitamin K1) and menaquinone (vitamin K2). While phylloquinone is abundant in green leafy vegetables and some vegetable oils, menaquinone is synthesized by microflora in the gut and is primarily derived from fermented food products (e.g. cheese). Although vitamin K is well known for its essential function in blood coagulation, substantial experimental evidence indicates that it also possesses an anticarcinogenic effect on a variety of cancer cell lines, including prostate cancer cells. To date, however, few epidemiologic studies have investigated the association between vitamin K intake and prostate cancer risk. Clearly, there is a critical need to explore this association because lack of such knowledge could hinder the elucidation of the etiology of prostate cancer and in turn the formulation of innovative measures for its primary prevention. We hypothesize that vitamin K is inversely associated with prostate cancer risk. Our hypothesis is novel but biologically plausible. We propose to test this hypothesis among all men in the screening arm of the PLCO Cancer Screening Trial. We pursue the two specific aims. Specific Aim 1: Calculate dietary intakes of phylloquinone and menaquinone from completed food frequency questionnaires; and Specific Aim 2: Evaluate the association between dietary intakes of phylloquinone and menaquinone and risk of prostate cancer. The proposed research is significant because our expected results will contribute to an improved understanding of the etiology and prevention of prostate cancer.