What drugs and foods interact with vitamin K?

There are several medications and foods that interact adversely with vitamin K, including the fat substitute olestra, blood thinners, phenytoin, certain antibiotics, orlistat (a weight-loss drug) and bile acid sequestrants. Usually, you can get your daily requirement of vitamin K from the foods you eat. It's abundant in broccoli, turnip greens, spinach, kale, asparagus, cabbage, green tea, beef liver and lettuce. It is also produced by intestinal bacteria. Foods containing olestra can inhibit vitamin K absorption, though many olestra products now contain vitamin K. Orlistat is a weight loss drug that works by preventing some fat from being absorbed, including fat-soluble vitamins such as vitamin K.