Which of the following nutrients helps regulate body processes?

Vitamins play a crucial role in regulating various body processes, making them essential for maintaining health and well-being. They serve as coenzymes and cofactors in numerous biochemical reactions, which include energy production, immune function, and blood clotting. Different vitamins are responsible for specific functions; for example, vitamin D influences calcium metabolism, while B vitamins are vital for energy production and the synthesis of red blood cells. Their regulatory functions help ensure that the body operates efficiently and supports overall physiological balance.

Other nutrients, such as proteins and fats, primarily serve different roles in the body, such as building and repairing tissues or providing energy. Minerals also have important roles, particularly in forming structures like bones or participating in nerve transmission and muscle contraction, but vitamins are specifically involved in the regulatory mechanisms that guide these processes. Therefore, vitamins are uniquely positioned as key players in regulating body functions, justifying their selection as the correct answer.