Iron is an essential mineral your body needs to produce energy, store oxygen and maintain other vital body functions. When you are deficient in iron, your body cannot make enough red blood cells and you become anemic.

Anemia occurs when there is a problem with the red blood cells. Women with anemia may lack sufficient red blood cells or their blood cells may contain low levels of the protein hemoglobin, which carries oxygen throughout the body.

A reduction in the normal amount of red blood cells in the body causes anemia. Red blood cells, which are produced in the bone marrow, contain hemoglobin molecules that carry oxygen to all parts of the body. If red blood cells decrease, hemoglobin and oxygen availability decrease accordingly, resulting in anemia.

In a healthy adult, each of the 20 to 30 trillion red blood cells in the bloodstream contains more than 250 million molecules of hemoglobin. This vital, iron-containing protein transports oxygen to the body tissues. An abnormally low hemoglobin level results in anemia.

Anemia is a condition marked by inadequate oxygen-carrying capacity of the blood. An insufficient number of red blood cells or an abnormally low amount of oxygen-transporting hemoglobin within the red blood cells can cause anemia. Anemias are commonly grouped according to the appearance of the red blood cells.

Vitamin B12 plays an integral part in red blood cell production. Red blood cells carry oxygen throughout the body, so either a decreased number of red blood cells or a lack of hemoglobin, the oxygen-carrying part of the cell, can cause anemia.

Anemia is a condition where your body produces an inadequate number of red blood cells. Anemia can also refer to a lack of the protein hemoglobin that makes blood red. Impaired blood cell production, heavy blood loss or diet deficiencies -- especially of B-12, folate and iron -- can all cause anemia.

Ferritin, a protein in the body, stores iron and releases it when needed, acting as a mediator and a transporter for iron. The amount of ferritin in the body is directly related to the amount of iron in the body.

Ferritin is a protein found inside cells. It binds to iron to hold onto it until the body needs to use it. Measuring the amount of ferritin in a child’s blood helps doctors figure out how much iron is being stored in the body.

If you were to look under the microscope at a sample of your blood, you would see scores of red, doughnut-shaped cells known as erythrocytes. Red blood cells number in the millions per cubic milliliter of blood and are the most numerous cell type in the body, according to University of Maryland Medical Center.

Microcytic anemia is a type of iron deficiency, and the term "microcytic" means "small cells" and refers to the appearance of iron-deficient red blood cells. These cells cannot deliver oxygen to target tissues as efficiently as normal cells.

Anemia often results in a lower than normal level of red blood cells due to a deficiency in iron. Without iron, the body struggles to make hemoglobin, a protein that transports oxygen from the lungs to circulate in the body.