(Child) IV fluids? Nutritional supplements? I'm trying to figure it out... I have a question.

Are infusion fluids and nutritional supplements the same thing?

My child has been sick for a few days, and now they have no energy and their mouth is very sore, so I'm thinking about giving them a nutritional supplement.

If I go to the hospital and talk about my symptoms and ask for an injection, will they give it to me?

Do you give injections based on the doctor's judgment?

And, I heard there's an oral infusion for pharmacies?? but they don't sell it at the pharmacy I go to.

Are there any pharmacies near the pediatrics and internal medicine departments?