Based on these scientific rationales, it is recommended that arginine should not be used in critically ill patients who are clearly septic. And many evidences exist for supplementation with antioxidant and immunonutrition in the critically ill. Glutamine and fish oil/borage oil should be considered. These result in the development of immune-enhancing diet (IED) without arginine. In addition, two types of lipids are added into the formula to further modulate immune response. First, fish oil as a source of omega-3 fatty acids and borage oil as a source of docosahexanoic acid (DHA), a unique omega-6 fatty acid (n-6 fatty acid). Both n-3 and n-6 fatty acids are polyunsaturated fatty acids (PUFAs) and are essential fatty acids (EFA). Therefore, immune-enhancing diet composes of L-glutamine, eicosapentaenoic acid (EPA), docosahexanoic acid (DHA), antioxidant vitamins and trace minerals such as vitamin A, vitamin E, vitamin C, selenium and betacarotene.