“…We have summarized the effects of provitamin A carotenoids on the vitamin A amount in livestock products which were shown in Table 2 . For the dietary supplementation with provitamin A carotenoids in the diet of poultry and livestock, it is not surprising that the different forms of vitamin A in the egg yolks, milk, and meat show increase ( Condron et al, 2014 , Heying et al, 2014 , Jiang et al, 1994 , Jin et al, 2015 , Miao et al, 2023 , Miao et al, 2023 , Prom et al, 2022 ). However, the absolute increased amount of vitamin A was still very limited in most cases.…”