Vitamins and trace elements are not energy carriers (dynamic nutrients) used in rations from 0.1 up to 0.3%. They are critical to improve energy and protein metabolism because of their involvement in enzymatic phenomena on a cellular level amongst (re-)productive tissues. They are key drivers to promote animal health due to their direct relation with the immune system. Many macro- and micro elements are associated with various vitamin syntheses and synergistic reaction to enzymatic functions. In dairy nutrition, supplementary feeding of vitamin and key trace elements can regulate growth rates, fertility, udder health, reduced SCC and improve productivity but also help the animals manage with inflammatory response. Low blood levels of Zn²⁺ and Fe²⁺ result to hypozincaemia due to the redistribution of those trace elements from blood plasma circulation to hepatocytes, therefore stored in the liver, in response to inflammation and endotoxins release in ruminants.₁ Vitamins considered as essential nutrients for optimum health and physiological functions. Vitamins have a catalytic function that facilitate nutrient synthesis, controlling metabolism and affecting the health and performance of livestock. In grazing dairy ewes, the dietary vitamin and trace mineral supplementation during dry season led to an increase of milk production and quality, with positive improvement in milk clotting aptitude.₂ In poultry nutrition, vitamins may improve the development of the intestinal mucosa and protect enterocytes from proapoptotic oxidant stress.₃ Studies showed that diets supplemented with vitamins and minerals play an important role in disease treatment because they act as hormone and enzyme activators and they allow animals to use proteins and energy for improving health, FCR, eggshell formation, growth, and reproduction.₄