Which complex chemicals are essential for normal body functions in humans and animals?

Vitamins are complex organic compounds that are crucial for various biochemical processes within the body. They play essential roles in metabolism, immunity, and overall health. Each vitamin has specific functions; for instance, vitamin A is important for vision, vitamin C supports the immune system, and the B vitamins are vital for energy production and cognitive function. Since vitamins cannot be synthesized in sufficient quantities by the body, they must be obtained through dietary sources, making them essential for normal bodily functions in both humans and animals.

While carbohydrates, proteins, and minerals are also important for health, they serve different purposes. Carbohydrates primarily provide energy, proteins are vital for growth and repair of tissues, and minerals are inorganic compounds that support various physiological functions such as bone health and fluid balance. However, vitamins specifically refer to the complex organic compounds that play a variety of critical roles beyond mere energy provision or structural support.