The primary function of nutrition in living organisms is to provide the necessary substances for growth, energy production, and cellular repair. Nutrients are typically categorized into macronutrients (such as carbohydrates, proteins, and fats) and micronutrients (like vitamins and minerals). Proper nutrition is essential for metabolic processes, enabling organisms to maintain homeostasis, support immune functions, and facilitate physiological functions. Inadequate nutrition can lead to deficiencies, affecting health and survival.