As you can see supplements are greatly debated but the only one that I am aware of that you have to be really careful of is the calcium's

I am Living proof that too much calcium in your diet can be really bad. For me it caused kidney stones.
NO I don't drink tea or carbonated beverages to excess.
so I don't want my little one having that problem.

Most of the supplements are water soluble so the frog can pee out the excess as long as it has plenty of water.
Now the fat soluble ones are a whole different ball of wax. Those you have to be careful of how much.
but there isn't too many of those in like flukers supplements.

But gut loading is the best by far.