Following a request from the European Commission, pursuant to Article 13 of Regulation (EC) No 1924/2006, the Panel on Dietetic Products, Nutrition and Allergies was asked to provide a scientific opinion on a health claim related to vitamin K2 and contribution to the normal function of the heart and blood vessels. The food constituent that is the subject of the claim, vitamin K2, is sufficiently characterised. The claimed effect, contribution to the normal function of the heart and blood vessels, is a beneficial physiological effect. The proposed target population is the general population. In weighing the evidence, the Panel took into account the absence of human intervention studies from which conclusions could be drawn for the scientific substantiation of the claim, the inconsistency of the results reported in two cross-sectional studies regarding arterial calcification in women, that the results of two prospective cohort studies are in conflict regarding the risk of coronary heart disease associated with vitamin K2 intakes, that high intakes of vitamin K2 were associated with a significantly lower degree of aortic calcification in one prospective cohort study after adjustment for confounders, and that the evidence provided for a proposed mechanism is weak. On the basis of the data presented, the Panel concludes that a cause and effect relationship has not been established between the dietary intake of vitamin K2 and contribution to the normal function of the heart and blood vessels.