It can accelerate the effect of the drug.You can eat green leafy vegetables if you are taking warfarin. But it’s important to eat the same amount of these foods each week to help keep your INR stable. This is because green leafy vegetables (e.g. spinach, broccoli, Brussels sprouts) are rich in vitamin K, which can affect your INR.
Don’t avoid vitamin K-rich foods completely — vitamin K is essential to our health. Studies show that eating regular, consistent amounts of vitamin K-rich foods is better for maintaining a stable INR, than not eating them at all, or eating varying amounts.