标题：Novel effects of diets enriched with corn oil or with an olive oil/sunflower oil mixture on vitamin K metabolism and vitamin K-dependent proteins in young men
出版社：American Society for Biochemistry and Molecular Biology
摘要：Little is known of how the fat components of diets influence the absorption and metabolism of vitamin K and the possible consequences to the synthesis of vitamin K-dependent (VKD) proteins in different target organs. We have evaluated the effects of two diets on circulating phylloquinone (K1) and triacylglycerols (TAG). One diet was enriched with corn oil (CO) (also rich in γ-tocopherol) and the other with an olive/sunflower (O/SO) mixture (rich in α-tocopherol). Effects on γ-carboxylation were assessed from coagulation assays and sensitive assays for undercarboxylated prothrombin (ucFII) and osteocalcin (ucOC). Total plasma matrix Gla-protein (MGP) was also measured. After an initial adjustment diet, 26 healthy young men were fed, in a crossover design, the O/SO or CO diet for 2 weeks. Mean intakes of K1 during consumption of adjustment, O/SO, and CO diets were 225 μg/day, 291 μg/day, and 291 μg/day, respectively. Mean fasting levels of TAG and K1 were both significantly reduced by the CO diet, but not by the O/SO diet. Neither diet reduced FII activity but ucFII became detectable in nine subjects, eight of whom showed this abnormality with both diets. The CO diet induced a rise in ucOC ( P r = −0.71, P We conclude that both oils, notably CO, affected vitamin K absorption and/or metabolism which may increase the requirements for γ-carboxylation. The mechanism is unclear but may result from interactions of vitamin K with PUFA and/or other lipid components such as vitamin E.
