Which of the following statements about selenium is true?

Selenium is indeed critical for the function of certain enzymes, particularly those that act as antioxidants in the body. One of the primary roles of selenium is as a component of selenoproteins, which include important enzymes such as glutathione peroxidases. These enzymes protect cells from oxidative damage by neutralizing free radicals, thus playing a vital role in maintaining overall health and preventing various diseases.

This function underscores why selenium is considered an essential nutrient, as it contributes significantly to metabolic processes and the body's defense mechanisms. While selenium is found in a variety of food sources, including nuts, grains, and meats, emphasizing its role in enzymatic activity is essential for understanding its value in nutrition and health topics.

Considering the other statements, selenium is classified as a trace mineral rather than a macromineral, which indicates it is required in smaller amounts. It cannot be synthesized by the body, meaning it must be obtained from dietary sources. Lastly, selenium is not exclusively found in animal products; it is present in various plant sources as well, especially those grown in selenium-rich soils.