I'm just beginning to cook from scratch for my health and a lot of recipes call to peel and discard the skins from fruits and vegetables. Now I thought that was where most of the nutrients were, or is that just the fiber? Because if I'm cooking it anyways, isn't the fiber destroyed?

Specifically I'm trying to make roasted red bell pepper soup for the vitamin C but the skins become extremely tough and pretty much impossible to chew.

I'm very new to this and would appreciate any tips, thank you!