The findings demonstrate that both
treatment factors were capable of increasing the vitamin D3
content in eggs, even though the UVB irradiation was more
effective than the dietary vitamin D 3 supplementation. Impor-tantly, we found that dietary vitamin D3 could increase the vitamin
D 3 content of egg yolk stronger in the group exposed to UVB than
in the group non-exposed to UVB radiation. Thus, by far the
highest content of vitamin D3 in eggs could be obtained with a
combination of UVB exposure and dietary vitamin D3.