Fat-soluble vitamins play essential roles in vertebrate’s development and homeostasis, and thus, an optimal, efficient and sustainable fish farming deeply depends on the optimization of their dietary levels provided. Subsequently, nutritional imbalances are considered one of the major causative factors of vertebrate’s abnormal development. Although approaches such as nutritional-dose-response trials, gene knock-down and over-expression studies, have provided valuable knowledge on its metabolism and dietary requirements; this knowledge is still mostly based on studies with mammalian species. Even though nutritional approaches involving different (i) research tools (i.e. NGS, RT-qPCR, proteomics, histology, immunohistochemistry, in situ hybridization, etc.), (ii) experimental approaches (in vivo and in vitro), and (iii) developmental stages (larval, juvenile and adult stages), have been applied to different fish species, the biological roles, underlying mechanisms and nutritional requirements in farmed fish are not fully understood yet. Here, knowledge gained during the last decade for each of the fat-soluble vitamins is compiled, reviewed from a holistic point of view, and the potential points of convergence of fat-soluble vitamins signalling pathways at molecular, cellular and tissue levels identified for the proper development of nutritionally balanced diets, based on integrative, multifactorial and multidisciplinary nutritional studies to be conducted in the nearest future.