Based on NIH | Is it safe to eat broccoli every day while taking warfarin, or will its vitamin K content interfere with my INR and require a dose adjustment?

Eating broccoli every day while taking warfarin can be safe for many people as long as the amount is kept consistent from week to week, because it’s the sudden change in vitamin K intake not the presence of vitamin K itself that most often disrupts INR. ^{[1] [2]} Consistent vitamin K intake helps your care team match your warfarin dose to your diet so your INR stays in range. ^{[3] [4]}

Why broccoli matters

• Broccoli is rich in vitamin K (phylloquinone), which the body uses to make clotting factors. Vitamin K can lower the effect of warfarin and reduce INR if intake increases significantly. ^{[5] [6]}
• Authoritative guidance emphasizes a “steady amount” of vitamin K rather than avoidance; abrupt increases or decreases may require warfarin dose changes and closer INR checks. Avoid “large amounts” or suddenly changing portion sizes. ^{[1] [2]}

What the evidence shows

• Controlled studies have found that a single serving of broccoli does not usually push INR outside the therapeutic range, but eating large amounts daily for about a week can shift anticoagulation toward clotting (lower INR), sometimes prompting dose adjustments. This suggests that routine, moderate, and consistent intake is generally acceptable, while sudden, high intake can interfere. ^{[7] [8]}
• Reviews indicate that people with very low and variable vitamin K intake often have less stable INRs; in some cases, maintaining a predictable vitamin K pattern improves stability. Keeping intake consistent can make INR control easier. ^[9]

Practical advice for daily broccoli eaters

• Keep it consistent: If you plan to eat broccoli daily, try to keep the portion (for example, ½–1 cup cooked) and cooking method similar day to day. Avoid sudden jumps like “none” to “two cups daily.” ^{[1] [6]}
• Coordinate with monitoring: Any change in your typical broccoli intake (more or less) should be paired with an INR check within about a week, because warfarin is a narrow-therapeutic-index drug and is sensitive to dietary vitamin K. Monitoring frequency should increase temporarily after diet changes. ^{[3] [10]}
• Balance your diet: You don’t need to eliminate vitamin K; aim for a normal, balanced diet with steady amounts of vitamin K–rich foods across the week. Talk with your healthcare team before making major diet changes. ^{[2] [5]}

Typical vitamin K context for broccoli

Vitamin K content varies by portion size and preparation and can change your weekly vitamin K “load.” While exact microgram values can vary by database and cooking method, broccoli is routinely listed among vitamin K–rich vegetables and should be counted as a meaningful source in your diet planning. The key is predictability rather than exact avoidance. ^{[6] [11]}

Practical portioning tips

• Keep to similar servings (for example, roughly ½–1 cup cooked broccoli at a given meal). Record your usual weekly pattern and stick to it. ^[9]
• If you like larger servings, that can be acceptable, but remain consistent and inform your clinic so they can align your warfarin dose with your regular intake. Avoid “feast or famine” patterns with greens. ^{[1] [3]}

When you might need a dose adjustment

• If you increase broccoli (or other vitamin K–rich foods like kale, spinach, Brussels sprouts) significantly and consistently, your INR may drop, and your warfarin dose may need to be adjusted upward to maintain your target INR range. Conversely, reducing vitamin K intake may raise INR and increase bleeding risk, potentially requiring a lower dose. ^{[6] [3]}
• Because diet is just one factor among many (other drugs, illnesses), any INR drift after a diet change should be evaluated by your care team with appropriate testing and dose guidance. Report planned diet shifts rather than surprising your monitoring team. ^{[3] [10]}

---

Bottom line

• Yes, you can eat broccoli daily on warfarin if you keep the amount consistent week to week. Sudden increases in broccoli (vitamin K) can lower your INR and may require a dose increase, while sudden decreases can raise your INR and increase bleeding risk. ^{[1] [6]}
• Work with your anticoagulation clinic to monitor INR when changing your broccoli or other greens intake, and maintain a steady dietary pattern to help keep your INR stable. ^{[3] [2]}