One example of an essential mineral in the human body is iron. Iron is an essential nutrient that plays a number of important roles in the body, including helping to carry oxygen in the blood, supporting the immune system, and assisting in the production of hormones. If a person is deficient in iron, they may experience symptoms such as fatigue, shortness of breath, and pale skin. To get enough iron, it's important to eat a diet that includes iron-rich foods, such as red meat, poultry, beans, and leafy green vegetables.