Background: Cardiovascular disease is the major cause of death in the Western world, but some recent studies indicate that vitamin K may play a role in atherosclerosis protection.
Aim of study: The aim of this study was to evaluate the effect of phylloquinone supplementation on blood lipids, inflammatory markers and fibrinolytic activity in postmenopausal women.
Methods: Thirty-one postmenopausal women completed this placebo-controlled, randomized crossover study and received 500 microg phylloquinone or placebo in addition to their habitual diet during two periods of 6 weeks' duration. Blood concentration of lipids, inflammatory markers and fibrinolytic parameters were measured after each period.
Results: Inflammatory markers, fibrinolytic parameters, total cholesterol and LDL-C were unaffected by the supplementation, whereas a 15% increase was seen in triacylglycerols (P = 0.015) and a 5% decrease in HDL-C (P = 0.06).
Conclusions: Six weeks supplementation with a dose of phylloquinone similar to that obtainable from the diet induced a deterioration of the lipid profile with no improvement in any of the other risk markers analysed. Thus, these results do not support a cardioprotective effect of vitamin K as has been suggested by others.