Vitamin nutrition in salmonid aquaculture: From avoiding deficiencies to enhancing functionalities

Recent advances in the role of vitamins as functional nutrients are challenging the established vitamin requirements of salmonid species. New generation aquafeeds that replace marine ingredients with more sustainable protein and omega-3 sources further highlight the need to revise the vitamin contents in salmonid feeds. Current farming conditions and genetic improvement indicate that basal requirements require revision to secure healthy fish production, optimise nutrient utilisation efficiency, and minimise nutrient losses. Cutting-edge research and current industry practices revealed that recommended levels of specific vitamins and other micronutrients must be revised to enhance survival, growth, and stress resistance, promote health and welfare, and improve food quality. The primary purpose of this review is to support the sustainable development of the salmonid aquaculture industry by optimising vitamin nutrition. This review summarises and evaluates the role of vitamins in salmonids and provides updates on vitamin inclusion levels in salmonid feeds. Understanding the interactions among vitamins and other nutrients could further contribute to sustainability by improving disease resistance and nutrient utilisation in salmonid aquaculture. •New generation aquafeeds drive the need to revise salmonids vitamin requirements•New findings of requirements for increasing dietary vitamins to combat stressors•Possible interactions among vitamins and other nutrients deserve further attention