What does the skeletal system primarily store in the body?

The skeletal system primarily stores calcium, which is essential for various bodily functions, including muscle contraction, nerve transmission, and blood coagulation. Calcium serves as a vital mineral that helps maintain the structural integrity of bones and teeth. The bones act as a reservoir, releasing calcium into the bloodstream when needed to regulate the levels of calcium in the body, which is critical for overall health.

In addition to providing support and structure, the skeletal system plays a crucial role in mineral storage and homeostasis. While other minerals like sodium and iron are important, they are primarily managed by other systems in the body. For instance, iron is mostly stored in the liver and bone marrow, while sodium balance is largely regulated by the kidneys. Therefore, calcium is specifically associated with the skeletal system, making it the correct answer.