Your skeletal system is the framework that your body depends upon to maintain its shape, to protect organs, and to produce movement -- the muscles couldn't operate if they weren't tethered to the bones. To serve its functions, the skeletal system needs a number of nutrients, including energy-providing molecules, vitamins and minerals.
Cells of the Skeletal System
All metabolically active body cells require nutrition -- the cells of the skeletal system are no exception. While most of the matrix of bone consists of a salt matrix that isn't made of living cells, live bone cells continually restructure and strengthen bones, and depend upon nutrients in order to do so. Furthermore, cells in the marrow of bones -- marrow fills the hollows at the center of long bones -- produce blood cells, and also depend upon nutrients.
All body cells, including the living cells of the skeletal system, need two types of nutrients. Macronutrients include proteins, carbohydrates, and fats. They're the energy-providing molecules that cells need in relatively large quantities, and skeletal system cells are no exception. Skeletal cells, like other body cells, also need micronutrients, or vitamins and minerals. With regard to the skeletal system, vitamins help cells to produce the products they make in order to fulfill skeletal function, while minerals form the basis of the bony matrix of your skeleton.
Calcium and Bones
One of the minerals most important to the function of the skeletal system is calcium; it serves as one of the principle ingredients for the salt that your cells use to build bone. Strangely enough, while calcium is critical to bone function, your body actually needs calcium in the bloodstream in addition to calcium in the bone, and regulates blood calcium more closely than bone calcium. In a way, the bones act as a repository of calcium for the blood, explains Dr. Lauralee Sherwood in her book "Human Physiology."
Because the blood can pull calcium out of the bone if blood calcium falls, and because loss of calcium weakens bone, it's very important that your skeletal system has access to plenty of calcium at all times. This is why you need calcium in your diet, but you also need vitamin D. Explain Drs. Reginald Garrett and Charles Grisham in their book "Biochemistry," vitamin D helps you move dietary calcium into the bloodstream for uptake by the bones -- without vitamin D, your bones become very weak.
Your skeletal system cells need other nutrients as well, including vitamin C, which cells use to produce cartilage, an important component of the skeletal system. Furthermore, however, blood progenitor cells located in the bone marrow need iron in order to build red blood cells. While blood cells don't seem at first to be a part of the skeletal system, the cells they come from are. Without sufficient iron, your bone marrow cells can't produce red blood cells, explains Sherwood, which can result in anemia.