Which of the following describes a major function of vitamins?

Vitamins play a critical role in regulating normal body functions, which encompasses a wide range of biochemical processes necessary for maintaining health. They are essential for various bodily functions, including metabolism, immune function, and cell division. Each vitamin serves unique functions; for instance, vitamin C is vital for collagen synthesis and immune health, while the B vitamins are important for energy metabolism and neurological function.

In contrast, building muscle tissue is primarily the role of proteins, which provide the amino acids necessary for muscle repair and growth. Vitamins do not directly contribute to muscle hypertrophy but support the processes that enable it, such as energy production and recovery.

Providing energy directly is not a function of vitamins; rather, macronutrients like carbohydrates, fats, and proteins supply energy that the body utilizes. Vitamins, however, act as coenzymes and assist in the metabolic pathways that convert these macronutrients into usable energy.

Lastly, vitamins do not function as a primary source of fat; dietary fats serve that purpose as they provide essential fatty acids and energy storage. While some vitamins are fat-soluble (like vitamins A, D, E, and K), they do not constitute a source of fat in and of themselves.