My understanding is that most of the vitamins and good stuff cereals claim to have are just sprayed on, rather than being inherent to the actual (bread, etc.) content.

As for the animals, ever seen side-by-sides of a wild animal's teeth with a natural diet, as compared to a similarly aged captive animal on a man-controlled diet? We could really stand to eat fewer preservatives and artificial flavorings, and more twigs and berries and bugs. At least it would mean fewer trips to the dentist.