"The Role of Vitamin K in INR Levels
Vitamin K is a key player when discussing INR levels. It's essential for the synthesis of certain clotting factors in the liver. Foods rich in vitamin K can increase INR, making it important for those on anticoagulants to manage their intake carefully. Leafy greens such as kale, spinach, and broccoli are particularly high in vitamin K. While these foods are nutritious, they can interfere with the effectiveness of warfarin by promoting clotting.
Conversely, reducing vitamin K intake can help lower INR levels. This doesn't mean completely eliminating these foods from the diet; rather, it’s about finding a balance. For instance, if someone usually consumes a lot of spinach, gradually reducing that intake while monitoring INR levels can be beneficial. It’s all about consistency."
Typically when on blood thinners they shoot for INR levels of 2.0-3.0, they say that is the therapeutic level to prevent clotting. Someone not on thinners will typically test around 1.0-1.5 I believe. I also know that when my dose of Warfarin is too high my INR levels increase to the 3.0-4.0 range, when my dose is too low I fall between 1.0-2.0. Higher INR test readings are "thinner" blood and lower numbers are "thicker" blood, too much vitamin K will make your INR test readings higher. Personally I never really saw any changes in my INR due to eating foods rich with vitamin K, maybe I didnt eat enough of it or one really needs to eat a lot to have much affect. For me what affected my levels the most was being ill with things like the flu or respiratory infections.
Another article that explains blood thinners and the effect of vitamin K