What is the primary role of vitamins in the body?

The primary role of vitamins in the body is to act as essential nutrients that facilitate various biochemical functions. While vitamins do support processes that are involved in cell repair and maintenance, they do not directly repair cells themselves. Instead, they assist enzymes and other molecules in carrying out the complex reactions required for the growth, repair, and overall health of cells and tissues.

Vitamins are crucial for processes such as energy production, immune system function, and the synthesis of hormones and other important substances. Each vitamin has a specific role; for example, vitamin C is vital for collagen formation, which is a key component in repairing tissues, while vitamin D is essential for calcium absorption and bone health.

Although options like providing energy, insulating the body, or building muscle involve other macronutrients or physiological processes, vitamins support these functions indirectly by ensuring that the body's systems operate efficiently. Thus, the correct answer emphasizes their role in supporting cell repair and maintenance through their involvement in metabolic pathways.