Antioxidant and Immune Effects of Vitamin K2

The aim of the study is to obtain insight into a dose-dependent effect of vitamin K2 on oxidative stress and specific markers of the immune system.

Inclusion Criteria:Self-reported postmenopausal (at least one year after the final menstruation)BMI ≥25 and ≤32 kg/m2;Plasma dp-ucMGP concentration in highest 50-66% of the screened populationNon-smoking, defined as not smoking currently and not having smoked (at all) in the year before study start;Healthy as assessed by the health questionnaire and according to the judgment of the study physician;Voluntary participation;Having given written informed consent;Willing to comply with study procedures;Exclusion Criteria:Plasma dp-ucMGP concentration >1000 pmol/L at screeningTreatment with oral antibiotics within 2 months of the start of the studyAny vaccination in the month before study start or any scheduled vaccination during the study periodUse of antioxidant or vitamin K and D supplements;Use of antioxidant or vitamin K and D supplements in the month before the start of the study;Use of aspirin or medication with established antioxidant or anti-inflammatory properties;Use of medication that interferes with vitamin K or blood coagulation;Use of statins to reduce level of low-density lipoprotein cholesterol in the blood;Hyperlipidaemia, diabetes, hypertension, intestinal disease, diseases with an inflammation component;Hormone replacement therapy in women;Follow a vegetarian or vegan diet;Participation in any clinical trial including blood sampling and/or administration of substances up to 30 days before day 1 of this study;Alcohol consumption for men > 28 units/week and >4/day; for women: >21 units/week and >3/day;Reported unexpected weight loss or weight gain of > 3 kg in the month prior to pre-study screening, or intention to lose weight during the study period;Reported slimming or medically prescribed diet;Recent blood donation (<1 month prior to Day 01 of the study);Not willing to give up blood donation during the study;