Yauheni Shastak

1 IntroductionVitamin A is an essential micronutrient that cannot be synthesized by non-ruminants and must be obtained through the diet. Although certain plant pigments called carotenoids may yield retinoids metabolically, only a small percentage of them can be converted into vitamin A precursors in mammals and birds (Surai et al., 2003; Combs and McClung, 2017). Due to practical considerations, t ...