I'm pretty sure it's fine. We used it early on the Drs recommendation. It's Not something you can overdose on. It can be given at each feed.
I'll have to disagree here - you can overdose on anything, even water. People on ecstasy can die from water overdose as the drug makes them think they are thirsty and they keep drinking and drinking and drinking. Apparently.

Anyway that's not the point. Point is, anything can be dangerous at a high enough dose.