This document discusses three minerals - calcium, iron, and zinc - that are essential to the human body. Calcium is required for muscle function and nerve transmission and is found mainly in bones, teeth, milk, yogurt and cheese. Iron is a major component of hemoglobin and carries oxygen throughout the body; a lack of iron can cause anemia. Good sources of iron include oysters, nuts and beef. Zinc plays a role in enzyme activity and cell growth and is found in foods like beef, lamb and sesame seeds. The document explores how these minerals support important bodily functions and where they can be obtained through diet.