Any of these items found in Pokémon media. A vitamin is a bottle of medicine. They are mostly identical in appearance, except for a change in the color of the label.
Protein (Taurine)
Iron (Bromhexine)
Calcium (Lysozyme)
Zinc (Chitosan)
Carbos (Indometacin)
HP Up (Max Up)
PP Up (Point Up)
PP Max (Point Max)
Note: For the Rare Candy, use rare_candy but don't use vitamin_(pokemon). Technically it's a vitamin too (according to Bulbapedia, see below), but its appearance is widly different. It's a blue wrapped candy.