Which of the following best describes the role of minerals in nutrition?

Minerals play a crucial role in nutrition primarily as co-factors in enzymatic reactions. This means they are essential for the activity of enzymes, which are proteins that catalyze biochemical reactions in the body. Many enzymes require specific minerals to function properly; for example, zinc is a co-factor for various enzymes involved in protein synthesis and DNA replication. By assisting these enzymes, minerals help facilitate a wide range of physiological processes that are vital for health, including metabolism, nerve function, and muscle contraction.

While the other options mention important physiological needs, they do not accurately capture the distinct role of minerals. Essential fatty acids are primarily supplied by fats and oils, hormones can be synthesized from other compounds including proteins and vitamins, and oxygen transport in the bloodstream is primarily performed by hemoglobin in red blood cells rather than minerals. Thus, the unique function of minerals as supports for enzymatic processes best encapsulates their role in nutrition.