Determination of phylloquinone and menaquinones in food - Effect of food matrix on circulating vitamin K concentrations

Fluctuations in international normalized ratio values are often ascribed to dietary changes in vitamin K intake. Here we present a database with vitam in K-1 and K-2 contents of a wide variety of food items. K-1 was mainly pre sent in green vegetables and plant margarins, K-2 in meat, liver, butter, e gg yolk, natto, cheese and curd cheese. To investigate the effect of the fo od matrix on vitamin K bioavailability, 6 healthy male volunteers consumed either a detergent-solubilized K-1 (3.51 mu mol) or a meal consisting 400 g of spinach (3.5 mu mol K-1) and 200 g of natto (3.1 mu mol K-2) The absorp tion of pure K-1 was faster than that of food-bound K vitamins (serum peak values at 4 h vs. 6 h after ingestion). Moreover, circulating K-2 concentra tions after the consumption of natto were about 10 times higher than those of K-1 after eating spinach. It is concluded that the contribution of K-2 v itamins (menaquinones) to the human vitamin K status is presently underesti mated, and that their potential interference with oral anticoagulant treatm ent needs to be investigated. Copyright (C) 2001 S.Karger AG, Basel.