Which of the following is considered a major mineral important for athletes?

Calcium is classified as a major mineral, which plays a crucial role in several bodily functions that are particularly important for athletes. It is essential for maintaining strong bones and healthy muscle function, which are vital for athletic performance. Adequate calcium intake is necessary to prevent bone density loss and reduce the risk of stress fractures, a common injury among athletes. Additionally, calcium is involved in muscle contractions and the signaling processes that initiate these contractions, making it integral to overall athletic performance.

Other minerals mentioned, while important, serve different functions. Iron, for example, is vital for oxygen transport in the blood but is classified as a trace mineral. Chromium and zinc also have roles in metabolism and immune function, but again, they are not classified among the major minerals in the same way as calcium. Therefore, calcium stands out as the key mineral for athletes to support their strength, performance, and overall health.