Minerals

For healthy people, supplements may help prevent vitamin and mineral deficiencies when the diet does not provide all necessary nutrients. They can also supply amounts of nutrients larger than the diet can provide. Larger amounts of some nutrients may help to protect against future disease.

Iron is an essential mineral. It is part of hemoglobin, the oxygen-carrying component of the blood. Iron-deficient people tire easily in part because their bodies are starved for oxygen. Iron is also part of myoglobin, which helps muscle cells store oxygen. Without enough iron, adenosine triphosphate (ATP; the fuel the body runs on) cannot be properly synthesized. As a result, some iron-deficient people become fatigued even when their hemoglobin levels are normal (i.e., when they are not anemic).