If you have a GOOD (Zoo Med or Arcadia) T5HO 10%UVB or higher
and it's mounted so it gives about 180-200 microW UVB / sq.cm at the basking spot
and about 100 microW UVB / sq.cm elsewhere ,
and the photoperiod is upward of 14 hrs per day .
The D3 Fortified calcium powder is not necessary. Dietary calcium from leafy greens and dusting with pure calcium powder , the dragon will produce all the vitD3 it needs in it's skin.