Vitamin K (K) is essential for blood coagulation and bone metabolism in mammals. K acts as a cofactor in the posttranslational synthesis of g-carboxyglutamic acid from glutamic acid residues. In addition to liver and bone, K is found in brain, heart, kidney and gonadal tissue. However, the physiological role of K in these varied organs is not yet fully understood. It is likely that K has functions in addition to its role as a cofactor of protein g-glutamyl carboxylation. In this paper we used DNA microarray techniques to identify the effect of K status on gene expression in rat liver. Expression of genes involved in the acute inflammation response was enhanced in rats fed a K-deficient diet relative to control and K1-supplemented diet groups. Moreover, dietary supplementation with K1 suppressed inflammation induced by LPS administration. These results indicate that orally administrated K1 suppresses inflammation in the rat.
