Aortic stenosis is a common heart valve disease and due to the growing elderly population the prevalence is increasing. The disease is progressive with increasing calcification of the valve cusps. A few attempts with medical preventive treatment have failed, thus presently the only effective treatment of aortic stenosis is surgery. This study will examine the effect of menaquinone-7 (MK-7) supplementation on progression of aortic valve calcification (AVC). The investigators hypothesize that MK-7 supplementation will slow down the calcification process.