When eating potatoes it's best to eat the skin along with the potatoes because when you remove the potato skin you're losing a lot of the nutrients and vitamins that the potato skin contains.
Potato skin contains B vitamins, vitamin C, iron, calcium, potassium and other nutrients and when you remove the potato skin and don't eat the potato skin you're losing out on those vitamins, minerals and nutrients that are needed to keep your body healthy.
Potatoes without skins are healthy too but you get more health benefits by eating both the potato itself and the potato skins as well.