As far as I know, normal Pedialyte doesn’t have any vitamins in it....
They do have a newer formulation called Pedialyte with Immune Support. That has (among others) Vit D3 and Vit B12 (?). I don’t know how easy it is to find or how much it costs compared to the standard type.
Personally...
Great idea— I keep it on hand always because it is a great rehydration option for people of all ages, and animals too.
OP—In case you don’t know, you can get pedialyte from any grocery store, & even most convenience stores...it’s in the baby section, near the formula, usually.