Which nutrient is primarily responsible for tissue growth and repair?

• A. Carbohydrate
• B. Fat
• C. Vitamin
• D. Protein

Answer: (D)

Protein provides the amino acids that build and repair tissues. Tissue growth and healing rely on new protein synthesis to form structural components like collagen and to replace damaged muscle proteins. If protein intake is insufficient, wound healing slows and growth is impaired because the body lacks the necessary building blocks. Carbohydrates and fats mainly supply energy to fuel these processes, but they do not provide the essential amino acids needed to construct tissues. Vitamins support metabolism and enzyme reactions involved in tissue maintenance, but they don’t serve as the primary building material for tissue synthesis.