Polyvisol vitamins

Has anyone given their newborn the Enfamil polyvisol vitamins with iron? It is 1 ml once a day given by mouth. My baby is 1 week 6 days old. The pediatrician prescribed it since we are exclusively feeding breastmilk.

I gave my baby their first dose this morning and he threw up, gagged, and 30 minutes later spit up a bunch of mucous. Also lost appetite and wouldn’t finish the bottle of milk. I did not want to mix into the milk because it smells horrible and I suspect my baby would not have drank the milk.

If anyone has given the polyvisol to their baby, what helped it go down better?