Any southerners out there? I need some help.

Here is what I know: Ground dry corn is called polenta and mush.
Dried corn that's been treated with wood ash, cal or lye is called hominy.

What the hell are grits?

Are grits the same thing as polenta? I've heard the term "hominy grits". Are these different than regular grits, having been treated? Or are all grits "hominy grits"? Is it regional within the south?

In Mexico, as we know, the process of removing the skin from the corn is nixtamalization. It makes the niacin available and stops the spread of pellagra, a vitamin deficiency disease heavy polenta eaters suffer from. Would heavy grits eaters suffer the same thing?

Any and old advice is welcome!