Which of the following best defines nutrients?

Nutrients are best defined as substances needed for growth, maintenance, and repair of the body. This definition encompasses the various roles that nutrients play in the human body, which include providing energy, supporting metabolic processes, and being essential for the synthesis of body tissues. Nutrients can be categorized into macronutrients (like carbohydrates, proteins, and fats) that provide energy and are necessary for growth, and micronutrients (like vitamins and minerals) that, while not primarily energy sources, are crucial for other body functions, including enzyme activity, immune function, and bone health. Thus, the comprehensive nature of nutrients not only addresses energy needs but also highlights their critical roles in overall health and biological processes throughout the lifespan, not limited to any specific stage.