Critical illness refers to life-threatening conditions characterized by systemic inflammation, immune system dysregulation, and failure of multiple organs, often resulting from severe infections, traumatic injuries, or respiratory complications. These conditions require intensive medical care and are associated with metabolic disturbances, suppressed immunity, muscle breakdown, and impaired gastrointestinal function. Pre-existing lifestyle and nutritional factors, such as malnutrition or obesity, play a significant role in influencing outcomes during intensive care. Data from Indian healthcare settings highlight a high prevalence of infections, physical frailty, and mortality, underscoring the importance of early preventive and therapeutic interventions. Nutritional support with immune-modulating formulations has shown potential in reducing hospital stay duration, complications, and death rates when administered early through the digestive tract. However, clinical outcomes vary due to differences in patient conditions, nutritional composition, and timing of support. Economic limitations and the need for tailored treatment plans also hinder broad implementation. Despite these challenges, nutrition-based immune support presents a promising strategy for improving recovery and should be further explored in critical care settings.