• DOI:10.1097/MCO.0b013e328011c46c
• Corpus ID: 20484616

Dietary vitamin K intake and anticoagulation in elderly patients

@article{Rohde2007DietaryVK,
  title={Dietary vitamin K intake and anticoagulation in elderly patients},
  author={Luis Eduardo P Rohde and Michelli Cristina Silva de Assis and Eneida Rejane Rabelo},
  journal={Current Opinion in Clinical Nutrition and Metabolic Care},
  year={2007},
  volume={10},
  pages={1–5}
}

• L. Rohde, M. C. D. de Assis, E. Rabelo
• Published 1 January 2007
• Medicine
• Current Opinion in Clinical Nutrition and Metabolic Care

Purpose of reviewVitamin K is an essential co-factor for the synthesis of several coagulation factors. Oral anticoagulants competitively inhibit enzymes that participate in vitamin K metabolism. The purpose of this review is to evaluate the potential interaction of dietary vitamin K and coagulation stability, particularly in the elderly patient. Recent findingsRecent prospective evidences suggest that dietary vitamin K plays an essential role in anticoagulation stability. Vitamin K intake of more than 250 μg/day was shown to decrease warfarin sensitivity in anticoagulated patients consuming regular diets. In a randomized crossover study, brief periods of changes on vitamin K intake also had significant effects on coagulation parameters. Patients that were allocated to an 80% decrease of intake increased International Normalized Ratio (INR) by almost 30% 7 days after the intervention. Similarly, it was estimated by dietary records that for each increase in 100 μg of vitamin K intake, the INR would be reduced by 0.2. A recent study also demonstrated that over-the-counter multivitamin supplements contain enough vitamin K1 to significantly alter coagulation parameters. SummaryContemporary data strengthen the concept that the interaction between dietary vitamin K and coumarin derivatives is clinically relevant and plays a major role in INR fluctuations in chronic anticoagulated patients.