The advice one gets on vitamin K is all over the place!
Warfarin is a vitamin K antagonist - it interferes with the way the body uses it. Vitamin K is used (among other things) as part of the clotting mechanism, so interfering with that mechanism reduces the chance of clotting. Some doctors and nurses then think that 2 plus 2 equals 37.6! You want to reduce the amount of vitamin K available for clotting, therefore vitamin K is bad, therefore don't eat it, and if you
do eat it, you are being very stupid indeed ... One nurse actually accused me of attempting suicide by continuing to 'eat my greens'! THIS IS ALL WRONG!
More sensible doctors understand that it is a case of eating a healthy diet including vitamin K, and then adjusting the drug dose to fit in with that! Research has shown that a good, consistent intake of vitamin K helps to stabilise INR levels.-
article.
I ate plenty of K-rich broccoli, iceberg lettuce, spring onions etc. while on Warfarin and my INR levels remained stable for 7 months. People eating only small amounts of vitamin K tend to have much more chance of dangerous fluctuations in their INR levels than those eating a healthier diet.
The crucial thing is to be
consistent. What you don't want to do is eat lots of vit K foods for a couple of weeks, then eat none for the next couple of weeks and so on ... If your diet is consistent, then the drug dose is more likely to be consistent, and
that is what you want.