Refining wheat, rice, etc. removes the nutrients--that's why they have to "enrich" them by adding nutrients back. Whole grain products already have these nutrients.
I wouldn't want to switch to white bread just because they put folate in it.
Good sources of folate (same as folic acid) are leafy green vegetables, such as spinach, turnip greens, etc. and these do not have high carbs. Also, most beans and some peas contain folate as does asparagus and brewer's yeast. It's pretty easy to get a list of foods by doing a web search.
Virtually all multivitamins contain the required daily amount of folic acid, and there are special supplements for women who are pregnant. Folic acid is a very important nutrient.
Thanks for mentioning this, ennay!