How Vitamin K–rich foods (kale, spinach, broccoli, other leafy greens) Affects Your Medications
You do not have to avoid greens — keep your vitamin K intake consistent from week to week and tell your anticoagulation clinic about major diet changes so your dose can be adjusted.
This interaction is generally considered moderate in severity.
How It Happens
Warfarin works by blocking vitamin K–dependent clotting factors. Large or inconsistent changes in dietary vitamin K can raise or lower warfarin's effect, changing your INR.
What to Do
You do not have to avoid greens — keep your vitamin K intake consistent from week to week and tell your anticoagulation clinic about major diet changes so your dose can be adjusted.
Medication Classes Affected
Specific Medications to Watch
This information is educational — not medical advice.
This page is provided for general educational purposes and summarizes publicly available data from sources such as the U.S. Food & Drug Administration. It is not a substitute for the judgment of a licensed clinician and should not be used to start, stop, or change any medication. It may be incomplete or out of date, and individual circumstances vary. Always talk with your prescriber or pharmacist about your specific medications and health conditions. If you think you may have a medical emergency, call 911.