Summary
Case reports cited in Medline or Biological Abstracts (1966-1996) were reviewed to
evaluate the impact of vitamin K1 dietary intake on the stability of anticoagulant control in patients using coumarin
derivatives. Reported nutrient-drug interactions cannot always be explained by the
vitamin K1 content of the food items. However, metabolic data indicate that a consistent dietary
intake of vitamin K is important to attain a daily equilibrium in vitamin K status.
We report a diet that provides a stable intake of vitamin K1, equivalent to the current U.S. Recommended Dietary Allowance, using food composition
data derived from high-performance liquid chromatography. Inconsistencies in the published
literature indicate that prospective clinical studies should be undertaken to clarify
the putative dietary vitamin K1-coumarin interaction. The dietary guidelines reported here may be used in such studies.