Final answer:
Proteins are required for the repair and building of intestinal tissues, as they provide the necessary amino acids for cell growth, replacement, and maintenance.
Step-by-step explanation:
The repair and building of intestinal tissues primarily require proteins. Proteins are essential for the growth and repair of all body tissues, including those in the intestines. They are involved in creating new cells, replacing old or damaged ones, and maintaining the individual structure of each cell, including those found in the intestinal lining where microvilli and villi absorb nutrients. An adequate intake of proteins ensures that the body has the necessary amino acids to perform these functions.
Carbohydrates, while important for providing energy and maintaining other bodily functions such as blood clotting and connective tissue health, do not directly contribute to the structural building and repair of tissues the way proteins do. Vitamins and fats, particularly fat-soluble vitamins (A, D, E, and K) absorbed with the help of dietary lipids, are also important but serve different roles, such as supporting immune function, bone health, and antioxidant protection, rather than directly building or repairing tissue.