Metabolic Bone Disease (MDB)
If it hasn't set in terribly yet, progress can be made. You can't really fix any major damage that has been done but you can make a difference in the "floppy/bendy" bones that will be noticeable. It depends how bad it is to begin with and how old the leos are. Since they are young, I bet you can help a lot.
Perhaps obtain some liquid calcium to jump start the process and do leave a bowl of calcium in the cages with them for free access. Usually I'd say No to D3 supplements but dusting the food with a calcium/D3 supplement a few times a week could be beneficial.
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Too many Leos
1.0 feline "Spot"
0.1 canine "Tika"