12mg daily is a lot but that's what it takes to keep my INR in range. the usual reaction I get when I tell medical people is 'How much??'.
I am not a big eater if greens so I can't point to that as the reason.
I guess its just the way I am.
In spite of this large dose, the adjustments made to alter the INR are still very small. If its low I am usually told to add about 0.5 or 1 mg for the next week (that's the total addition for the week, not per day).
Its a fickle thing!
Chris P.