I only use supplements regularly for dart frogs, since those poor things only get fruit flies for food. For other frogs, the only supplements they get are the occasional calcium-dusted food item. They do however get a varied diet and whenever I feed with crickets, these are gut-loaded prior to feeding.

For the darts, I started out using herptivite and repcal, but having done a lot of reading and talking with dartfrog enthusiasts, sticking with just those two seems to lead to subtle nutritional deficiencies like raised frequency of SLS in tadpoles. So now I rotate herptivite, repcal, Repashy Calcium+ICB ("Instant Cricket Balance") and Repashy Supermin. Incidentally, I bought those last two from Ron at AlphaProBreeders, one of our sponsors.