t take a multivitamin or anything containing
folic acid. The reason for this is, mtx and
folic acid compete for the same chemical receptors in your body, so taking folic acid with mtx will reduce the effectiveness of both.
The beneficial action of the mtx causes a folic acid deficit, which is why you have to "rescue" with extra folic acid a day later. Taking additional on the other days may help ease some of the side effects.