Generally it is not advised to stop folic acid when you take the methotrexate. The reason for this is that mtx and folic acid are one chemical structure bond different from each other. Folic acid is used to work as a "rescue" to stop the chemo damage on healthy cells. When taken for cancer, chemotherapy is not wanted to slow it down at all. BUT when you take it for an autoimmune disease, you don't want the damage on healthy cells. Talk to your doctor or hematologist/oncologist about this.
I've been on methotrexate for 17 years. Unless I am hospitalized for an infection, I don't skip doses. I've found that I have more problems if I do quit it, than if I just carry on.
I've put a synopsis of my mtx history down under cytotoxic drugs. It gives a more detailed reason for why things get done a certain way.
Before lupus, I was doing all my pre req's for nursing school. As part of the pre req's, I had to take organic chemistry. It was a tough class, but one I have used more than any other in trying to explain to people why things get done a certain way.
If I can help with any answers, experiences, survival, you can post or IM me. Either way, I am more than happy to share the ways I have learned to live with it.
Sally