Galleria mellonella L. (Lepidoptera: Pyralidae) larvae were reared on an artificial diet containing vitamin D-3, also known as cholecalciferol, at concentrations of 0.01, 0.10, or 1.00% (g/100 g of diet) to the adult stage under laboratory conditions. Survival rate and development through adult emergence were observed and recorded. Survival rate in postlarval stages was significantly reduced in response to increased vitamin D-3 concentrations. The tested concentrations of vitamin D-3 (0.01-1.00%) decreased adult emergence in comparison with the control; however, only the highest concentration (1.00%) prolonged the duration of the adult stage. The 1.00% concentration also significantly reduced pupal survival rate from mean (+/- standard error) of 85.00% +/- 0.35% to 63.75% +/- 1.14% for pupation, whereas adult emergence decreased to 42.50% +/- 0.25%. However, it prolonged the duration of adults from 40.67 +/- 1.80 d for the control to 46.07 +/- 2.28 d. Although the highest concentration showed a prolongation in duration of the pupal and adult stages, we observed no statistical effects compared with the control group. Our results, however, indicate that vitamin D-3 may play a fortifying role in development as a nutritional additive for larval development, or as a toxin that may be used in small concentrations on postlarval developmental stages. Further research should assess if increased concentrations improve or deteriorate life table parameters in target insects.