Iron is vital to your body's health, functioning as a trace element required to form red blood cells. Your marrow contains 10 times more iron than the amount in your blood plasma. Anemia develops when your body does not have enough red blood cells due to a lack of iron or hemoglobin. It can also be caused by other nutrient deficiencies and diseases that harm the gastrointestinal tract. Iron Deficiency Anemia However, you may also be at risk of developing iron-deficiency anemi