Dietary Vitamin K and Association with Hepatic Vitamin K Status in a Yup'ik Study Population from Southwestern Alaska

• Published in: Molecular Nutrition & Food Research
• Main Authors: Au, Nicholas T., Ryman, Tove, Rettie, Allan E., Hopkins, Scarlett E., Boyer, Bert B., Black, Jynene, Philip, Jacques, Yracheta, Joseph, Fohner, Alison E., Reyes, Morayma, Thornton, Timothy A., Austin, Melissa A., Thummel, Kenneth E.
• Other Authors: National Institutes of Health
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2017
• Subjects: Pivka; Tundra; Yup'ik; Alaska
• Online Access: http://dx.doi.org/10.1002/mnfr.201700746; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fmnfr.201700746; https://onlinelibrary.wiley.com/doi/pdf/10.1002/mnfr.201700746

Scope The relationship between dietary vitamin K and plasma PIVKA‐II concentration, a biomarker of hepatic vitamin K status, in a Yup'ik study population in southwestern Alaska is investigated. Methods and results A total of 659 male and female, self‐reported Yup'ik people, ≥14 years of age, were enrolled. Blood is collected for genotyping and plasma PIVKA‐II biomarker analysis. A Yup'ik‐specific dietary food frequency questionnaire is used to assess vitamin K intake. Among the participants, 22% report not consuming foods rich in vitamin K during the past year and 36% have a PIVKA‐II concentration ≥ 2 ng mL –1 , indicating vitamin K insufficiency. The odds of an elevated PIVKA‐II concentration are 33% lower in individuals reporting any versus no consumption of vitamin‐K‐rich foods. The association is significant after adjusting for CYP4F2*3 genotype. Tundra greens are high in vitamin K1 content, but an exploratory analysis suggests that subsistence meat sources have a greater effect on vitamin K status. Conclusions A substantial proportion of the Yup'ik population exhibits vitamin K insufficiency, which is associated with low consumption of vitamin K rich foods and which might affect an individual's response to anticoagulant drugs such as warfarin that target the vitamin K cycle.