I was under the impression that Super Worms weren't the best nutrionally, but perhaps I'm wrong.

But with most things, generally you shouldn't get involved with things you don't know about. If your not absolutely sure, I'd stop and research first.

But, if he's been eating them for a while now with no incidents or problems, it should be okay. Keep a close eye on him any how, but it sounds like you've been feeding them to him for a while now, and nothing bad has happened yet, so perhaps it's fine.

Maybe someone else will chime in and give their opinion/knowledge