Based on PubMed | Is it true that eating yogurt can interfere with warfarin and change my INR levels?

Eating yogurt in typical amounts does not usually interfere with warfarin or meaningfully change INR, as yogurt is low in vitamin K; the key with warfarin is keeping your overall vitamin K intake steady from week to week. ^{[1] [2]}

How warfarin and diet interact

• Warfarin works by blocking vitamin K’s role in clotting; large or erratic changes in vitamin K intake can lower or raise your INR. ^{[3] [4]}
• Authoritative guidance recommends a normal, balanced diet and, most importantly, a consistent amount of vitamin K rather than strict avoidance. Big swings in vitamin K–rich foods are what tend to shift INR. ^{[1] [2]}
• Foods highest in vitamin K are leafy green vegetables and certain plant oils (soybean, canola), which can decrease warfarin’s effect if eaten in large, inconsistent amounts. ^{[4] [2]}
• Overall, maintaining a steady pattern helps INR stability and avoids surprises. ^{[1] [5]}

Where yogurt fits

• Plain dairy products like milk and yogurt are generally low in vitamin K compared with leafy greens and do not appear on standard “high‑vitamin K” food lists of concern for warfarin. Therefore, typical servings of yogurt are unlikely to lower INR. ^{[2] [5]}
• The main dietary factor linked to INR shifts is vitamin K variability, not dairy intake per se. ^{[1] [5]}

Probiotics and warfarin

• Some yogurts contain live cultures (probiotics). Evidence directly linking probiotic foods to consistent INR changes is limited and not well established. Official guidance emphasizes monitoring INR with any new supplement or botanical rather than routine foods like yogurt. ^[6]
• If you start a high‑dose probiotic supplement (pill form) or significantly increase probiotic foods, it is reasonable to check INR a bit sooner, as individual responses can vary and research is not definitive. ^[6]

Practical tips for yogurt lovers on warfarin

• You can include yogurt as part of a balanced diet; try to keep your overall eating pattern stable week to week. Consistency is more important than avoidance. ^{[1] [2]}
• Be cautious with sudden diet overhauls, especially big increases in leafy greens or vitamin K–fortified products, which can reduce INR. ^{[4] [7]}
• Avoid vitamin K2 (menaquinone‑7, “MK‑7”) supplements, which have been shown to lower INR even at low doses; these are supplements, not standard yogurt. ^[8]
• If you introduce new supplements, herbal products, or make major dietary changes, arrange an INR check to stay within your target range. ^{[3] [6]}

Bottom line

• Yogurt itself is not typically a problem for warfarin and INR when eaten in normal amounts and as part of a consistent diet. Focus on keeping vitamin K intake steady and be cautious with supplements, especially vitamin K2. ^{[1] [2] [8]}

---

Would you like help reviewing your usual weekly diet to spot any vitamin K swings that could affect your INR?