Re: trying to conceive
folic acid is taken to prevent birth defects like spina bifida. you need it most in the first three months of your pregnancy so its good to have a buildup of it in your system. if you are planning a pregnancy, then yes, you should take it from about 3 months before, along with a multivitamin, so you have enough in your system.
http://www.phac-aspc.gc.ca/fa-af/index-eng.php - more info