Still need clarification on what foods, etc. would have an effect on warfarin. My numbers keep changing. I am now on 9mg and 6mg. Don't want

I don't want my warfarin to go above 9 mg. wich I am now taking 6mg and 9mg. What would make the warfarin keep going up?? Is it greens, is it vitamins such as bilberry. I don't understand what makes the dosage go up or down. How can i research this? Where can I get an explanation of why my dosage keeps changing. I'm lost. Thanks.

12 Replies

  • The amount you take matters not at all. The only thing that does is the INR . If you constantly change diet then you will have problems staying in range. I know of people on 2 mg and others on 15+ all for INR 2.5. Try to keep a steady intake of all foods but obviously avoid those things like high Vit K greens and look at the yellow book do's and don'ts. Some things like alcohol increase INR whilst others reduce it. AF-Association have a fact sheet on the main website which may help. We all metabolise warfarin at different rates hence the variation. Make your dose fit your lifestyle not the other way round usually works best.


  • Or.........ask your consultant about warfarin alternatives - dabigatran, rivaroxaban and apixaban. You can read about these on the AFA website.

  • I tried 2 of the new drugs that one does not have to be bothered with warfarin blood etc.

    I had a bad effect from both of them and rushed to get back to warfarin where i have no digestion problems, etc.

  • Hi Paulina,

    That's a rather strange dose - 6mg and 9mg. I'm on 8mg every day and that's fine for me - one pink and one blue tablet p.d. The key thing is to have a steady intake of Vit K. I achieve that by taking a Vit K tablet which effectively buffers my Vit K intake. I would however only suggest a tablet if you know exactly what you're doing.

    In your case you could try a steady intake of high Vit K food per day - e.g. 4 florets on brocolli or a measured amount of spinach - and not worry about a steady intake of food that has less Vit K.

    If you want to research it, I suggest you keep a food diary and lookup the Vit K content of everything you eat to identify what is causing the variability.


  • Mark, I noticed in earlier posts that you take vit K tabs. Have you been given the OK by medics to do this? It doesn't sound quite right to me that you are ' adjusting' your INR levels this way rather than more natural means of diet. Otherwise why wouldn't we all take vit K? I'm sure you will put me right on this! Sandra

  • Hi Sandra,

    I posted on this a couple of weeks ago. There's been quite a lot of research showing that a Vit K tablet helps stabilise INR. I haven't discussed it with my GP, who wouldn't understand, but my EP, Prof Schilling, is in favour. I don't adjust my INR using the Vit K tablet. I just take 90mcg of Vit K2 per day and then variations due to diet become largely irrelevant. Consequently I get INR in range 99% of the time, which provides better protection than any of the new Anti-Coags.

    Our bodies need Vit K, particularly Vit K2 (which can be metabolised from ordinary Vit K), to ensure calcium is deposited in bones and not in arteries causing artherosclerosis. The worst thing to do on warfarin is minimise Vit K intake. You then get the double whammy of unstable INR and greater risk of furring up of arteries.

    Should we all be taking Vit K of one sort or another? In my view yes, but we do have to battle old-fashioned thinking by a lot of doctors.


  • Thanks Mark...that's really interesting

    I do not currently have problems staying in range but I shall look into this further. Sandra

  • I agree with Mark- usually you would have the same every day (Warfarin) or say, 7mg on some days and 8mg on the others rather than 3 mg difference- I think that might partly explain the INR variation.

  • Mark, where do you get your Vit K tablets? I am thinking of taking some with me in case my INR goes high whilst out in the Far East.

  • Hi Barb,

    I get the Jarrow formula Vit K2 MK-7 through Amazon from a company called United Care. They were GBP12.21 for 60 softgels last time I bought some. I take them every day rather than stopping and starting. I had to increase my warfarin by about 0.5-1mg when I started. But please do your research before so you understand the effect they have. I included some references in a previous post.


  • Yatsura I 'm sure Mark will explain better than I but he's got a sound idea- if he takes Vit K daily any change in the Vit K from food is a much smaller % change of his whole intake of Vit K

    Barb1 I have found spinach brings my INR down very quickly but it has then dropped below range if I've had too much spinach- it depends whether you are in AF as to the overall balance of risk from adjusting like that!

  • Sorry Paulina for hijacking this post. I am not sure what to do. Take the Vit K tablets or stop the warfarin and eat the spinach - if I can find any!

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