[deep-root]

Check out the ingredients of Cheerios, which says a bit about the process of making them and the attempt to restore some nutrition: https://www.wdbqschools.org/Downloads/Cereal-Cheerios.pdf

Probably Wonder Bread would look similar, but homemade bread quite different. All are processed foods of some level due to flour.

[nitwit005]

We've been deliberately fortifying foods since the 1930s to try to reduce incidence of diseases caused by lack of some vitamin or other micronutrient, which has seemed to be effective. You're required to add it for some products, although I believe quite a bit is still voluntary.