Comparison of phylloquinone bioavailability from food sources or a supplement in human subjects

Phylloquinone (K) absorption was assessed in 22- to 30-y-old human subjects consuming a standard test meal [402 kcal (1682 kJ), 27% energy from fat]. The absorption of phylloquinone, measured over a 9-h period as the area under the curve (AUC), was higher (P < 0.01) after the consumption of a 500-mu g phylloquinone tablet [27.55 +/- 10.08 nmol/(L.h), n = 8] than after the ingestion of 495 mu g phylloquinone as 150 g of raw spinach [4.79 +/- 1.11 nmol/(L.h), n = 3]. Less phylloquinone (P < 0.05) was absorbed from 50 g of spinach (AUC = 2.49 +/- 1.11 nmol/(L.h) than from 150 g of spinach. Absorption of phylloquinone from fresh spinach (165 mu g K), fresh broccoli (184 mu g K) and fresh romaine lettuce (179 mu g K) did not differ. There was no difference in phylloquinone absorption from fresh or cooked broccoli or from fresh romaine lettuce consumed with a meal containing 30 or 45% energy as fat.