Inclusion Criteria:  Age ≥ 18 years At least 3 months on PD Life expectancy of ≥ 18 months  Exclusion Criteria:  Liver disease Drug or alcohol abuse Pregnancy or breast-feeding Treatment with phosphate binders (sevelamer) Ongoing malignancy or severe inflammatory disease diagnosis Use of vitamin K antagonist or vitamin K supplements during the past 3 months Diagnosis of severe gut-disease (inflammatory or short bowel disease) or gastrointestinal malabsorption Mental disorder rendering the patient unable to conform with the instructions and fully understand the nature, aim and possible side-effects of the supplementation