Two strains (University of Saskatchewan, white egg and wild type) of mature Japanese quail (Coturnix coturnix japonica), following a 4-week depletion period, were fed one of four diets varying in supplementary vitamin D3: a) no supplementary vitamin D3, b) National Research Council (NRC, 1977) recommended level of 1,200 IU vitamin D3/kg feed, c) 10 times, NRC levels, and d) 100 times NRC levels for 4 weeks. Egg production, egg weight, number of soft-shelled eggs, body weight, and feed consumption were not affected by vitamin D3 treatment. Hatchability of the white egg strain was not affected by vitamin D3 treatment. Hatchability in the wild type strain was reduced in those birds consuming diets unsupplemented with vitamin D3 although not significantly. Tibia ash was not affected by vitamin D3 treatment.Progeny from hens receiving no supplemental vitamin D3 were smaller throughout a 5-week growth period; however, feed consumption and percentage tibia ash content were similar to those of progeny from the other treatments. Progeny fed 480 IU vitamin D3/kg feed were larger, had higher tibia ash, and similar feed consumption compared with those fed a diet with no added vitamin D3.