White flour is absolutely nutritionally devoid – even if it has been enriched. The processing of white flour means that the germ and the bran have been removed, and all that is left is the endosperm. The nutrient-rich oils are located in the bran, and most vitamins and minerals are located in the germ. When these two things are processed out, you are essentially left with nothing but starch.
This starch is then bleached, and this further reduces its nutritional status. In the end, you have a substance that turns into paper Mache in your body, which is highly acidic and provides your body with no nutrition. The synthetic vitamins that are added back into enriched flour are not utilized by your body as efficiently as the natural vitamins and minerals that would have been in the plant had it not been processed at all.
Substitutes: Whole grains! Go for whole wheat, spelt, rye and oat. You may even want to experiment with sprouted grain products, and gluten-free products – just be sure your gluten-free products are not also fully processed and filled with refined grains.