Iron is an essential nutrient for humans, as well as for many other forms of life. In humans, it helps regulate cellular respiration, providing the main source of energy for many different cell types in the body to do their work. It is also a major component of red blood cells, which provide oxygen to all parts of the body and return carbon dioxide to the lungs for expiration. Iron also helps store oxygen within muscle cells.

When you realize how important iron is to human life, it may become clear that a deficiency in this nutrient can cause serious problems. Perhaps the most well-known symptom of iron deficiency, and the most critical, is iron deficiency anemia, in which the bone marrow has insufficient iron to produce the hemoglobin that goes into healthy red blood cells. As a result, the bone marrow of a person suffering from iron deficiency anemia produces fewer and smaller red blood cells than that of a healthy person. Eventually, this can lead to reduced oxygen supply to the organs and resulting organ failure and death.

Iron deficiency can be caused by excessive bleeding, inadequate intake of iron, or a diet or medical problem that interferes with the body's absorption of iron. Women are ten times as likely as men to develop this condition due to the blood lost during menstruation. Iron deficiency anemia is the end stage of iron deficiency, but problematic symptoms can arise even before anemia sets in. Such symptoms should always be taken seriously and discussed with your doctor, as iron deficiency anemia can be life-threatening and may be preventable with early treatment.

Some symptoms of iron deficiency are fatigue, light-headedness, muscle weakness, irritability, a very pale appearance, and pica - an eating disorder in which the sufferer craves non-food items like clay or chalk. In addition to these symptoms, full blown anemia may also present with hair loss, shortness of breath, fainting, constipation, heart palpitations, ringing in the ears, visual hallucinations, sensations of numbness or burning, and rarely, sleep apnea.

Iron deficiency can be prevented in many cases with a proper diet or with the use of iron supplements, unless it is due to malabsorption. Iron-rich foods include meats of all kinds, green leafy vegetables, beans, and tofu. Always discuss any health concerns or planned changes in your diet with your doctor. This article is not intended as a guide to diagnosis.