What is a nutrient?

A nutrient is defined as a substance that the body ingests and utilizes for various physiological functions. Nutrients are essential for growth, maintenance, and repair of tissues and play vital roles in metabolic processes. They provide the necessary energy and building blocks for various bodily functions, including the production of hormones, enzymes, and other important molecules.

In contrast, the other options do not align with the scientific definition of a nutrient. While medications can affect bodily functions, they are not classified as nutrients because their primary purpose isn't to provide nutritional support. Similarly, substances used primarily for cooking, such as oils or spices, may enhance flavor or texture but do not inherently nourish the body. Lastly, artificial ingredients, while sometimes added to foods for preservation or enhancement, are not considered nutrients unless they offer nutritional value. Therefore, the understanding that nutrients are key substances consumed for bodily health and energy solidifies option C as the correct choice.