Hi Alicia-
Joe's been on Coumadin 25 years. We are just "careful" with vitamin K foods. Everyone needs to eat a little green stuff for health. Like everyone else has said, it's moderation which is the key and being consistent.
And we don't agonize about his INR numbers. We always ask what the INR is so we know and can sort of track how it's going for Joe. Only occasionally is he too far out of range. It gets taken care of easily. He has a good doctor monitoring him.
The one situation which is troublesome, is when his regular doctor is not doing the monitoring, i.e. when he's on vacation, or also when Joe has been in the hospital and others are doing the regulation. That's a real watch area, and that's where knowing what his INR is at all times is so important. I've caught many errors, from some pretty surprising sources, people who absolutely should have known better.