What is a primary function of vitamins in the human body?

Vitamins play a crucial role in various biochemical processes in the human body, with one of their primary functions being to support immune function and facilitate cell repair. Many vitamins, such as vitamin C, vitamin A, and the B vitamins, are essential for the proper functioning of the immune system. They aid in the production and activity of immune cells, enhance the body's ability to fight off infections, and are vital in the healing processes following injury or illness.

In addition to immune support, vitamins contribute to cell repair by serving as cofactors for enzymes involved in cellular processes, including DNA synthesis and repair mechanisms. For instance, some vitamins are integral in the synthesis of collagen and other proteins necessary for the maintenance of healthy tissues and organs.

While providing energy is a key function of macronutrients such as carbohydrates, fats, and proteins, vitamins themselves do not provide energy directly. They are involved in metabolic processes that aid in energy production, but they do not serve as a direct energy source. Additionally, vitamins are not structural components of cells in the way that proteins, lipids, and carbohydrates are. Finally, the regulation of body temperature is primarily managed by physiological mechanisms and is not a direct function of vitamins. Thus, the correct choice highlights the vital role