Final answer:
Selenium toxicity is indicated by loss of appetite, headaches, and impaired immune function. It's important to balance mineral intake to avoid such issues.
Step-by-step explanation:
The mineral toxicity that is characterized by symptoms such as loss of appetite, headaches, and impaired immune function is Selenium toxicity. Although minerals like iron, zinc, and copper are essential for various bodily functions, excessive amounts of these can lead to negative health effects. In this case, selenium is known to cause the listed symptoms when present in high concentrations in the body. It is crucial to maintain a balanced intake of minerals to prevent such toxicities.