There are other water-soluble vitamins that break down when frozen, given time. However, I think that anyone feeding f/t that goes through their frozen stock at least once every 6 months has little to worry about nutrition-wise.

That being said, there have not been any studies done on the nutritional needs of ball pythons, so we don't really know if they are being hurt or helped from eating frozen rodents.

What we do know, however, is that many keepers have raised many healthy ball pythons on f/t rodents. Regardless of the freezing effect on nutrients, I think that speaks for itself.

I still prefer to feed live food, though...but not for nutritional reasons...