I'm not sure about the arguing stuff going on. Yes, K2 is entirely different from K1, it has no effect on warfarin's functions, but I wonder, somethimes, about how well they isolate K2 from K1 (or if they use different sources). I certainly don't want any K1 in my K2. That's my only concern about it. (I'll have to look up where they're getting the K2, and see if there's any possibility of a crossover with K1).
I accidentally misread the dosage on my wife's K2 pills and was off by a factor of 100. I took them for several days. My next INR at the lab dropped from 3 to 1.5. I stopped taking them and increased my warfarin in conjunction with my coumadin clinic's recommendation. After a week, my INR shifted significantly upward. Then after a second week, it shifted significantly upward again. Rereading the label, the K2 was half K2 mk7 and half K2 mk4. Reading on the internet, MK4 has a half life of about a week. MK7 has a half life of aout 2 weeks which is why it is supposed to be better for bone strength. Protime's remark about "your meter is your friend" is the way to approach it.
Right now I am still in the process of rigorously correlating my meter with the Lab Test measurements. When I am done with that, probably this summer, I will revisit K2 and treat the mk4 and mk7 in two different sequences with different pills.
Note: K2 mk4 is present in grass fed meats and dairy products. Also in free range and pasture raised chicken to a very large extent and in all chicken products (and eggs) to a lesser extent. Because the extent of "grass fed" may change from Spring to Summer to Fall to Winter, if you eat meat, eggs or dairy, check frequently. As the seasons change so will the amount of K1 and K2 you eat.
Again, your meter is your friend. I plan on taking the smallest pill size I can find, splitting it in two and incrementing very slowly to see whether I can find a good dose that does not affect my INR significantly. I also need to find out whether the two week half life for mk7 is accurate because I do not wish to have to wait for two weeks if K2 mk7 does affect my INR signficantly.
Again, many thanks to the many members of this forum for their tips on how they use their meters. My meter as currently calculated predicts the Lab INR within 0.15 units most of the time even though it is off - before the regression equation the difference between the meter is 0.2 to 0.4 units. The charts of the three data series
1) Coag-Sense INR,
2) Lab INR,
3) Predicted Lab INR based on Coag-Sense INR
move in lockstep up and down. Statistics is wonderful. Many thanks to the University of Utah Anti-Coagulation Clinic for publishing papers on how to do this and pointing out that it is Statistics 101 stuff that can be calculated and plotted in Microsoft XL or Apple Numbers.
See what you doctors and pharmacist say and then approach it very gradually. I did that with K1 and it worked. The approach, especially with your meter, should work perfectly. I have adapted to several medicines and supplements that are supposed to interfere with Coumadin by this approach (albeit, before I had my Coag-Sense). After getting my meter, I adapted Protime's approach described above and it works. Small mid-course adjustments with minimal to no rebound effects are much better then big adjustments with possible big rebound effects.
Walk in Peace,
Scribe With a Lancet