Dietary vitamin K intakes and their relationship with metabolic syndrome in U.S. young adults

Abstract

The relationship between dietary intake of vitamin K and metabolic syndrome (MetS) has not been previously investigated. Data from 5,800 adults aged 20 to 45 years in the National Health and Nutrition Examination Survey (NHANES) 1999–2004 were analyzed. Dietary vitamin K was measured as phylloquinone. MetS was defined according to the Adult Treatment Panel III criteria. Prevalence and odds ratios (OR) of MetS and its components were assessed by quartiles of dietary phylloquinone intake. Lowest prevalence of MetS and its five components was observed in individuals with highest phylloquinone intakes. Prevalence of low high density lipoprotein (HDL) cholesterol levels and elevated blood pressure progressively decreased with increasing phylloquinone intake (p<0.05 for trend). Compared with the lowest phylloquinone intake quartile, the highest quartile of intake was associated with significantly reduced risks of low HDL levels, hypertriglyceridemia and hyperglycemia after adjustment for various confounding factors [OR 0.73 (95% CI 0.45–0.98), OR 0.51 (95% CI 0.25–0.97), and OR 0.18 (95% CI 0.05–0.73), respectively]. Our results suggest that high dietary phylloquinone intake may favorably affect MetS or its components. The mechanism(s) underlying the observed associations between phylloquinone and MetS needs to be elucidated and the role of vitamin K nutriture in MetS merits further investigation.