These iron losses in women double their need to absorb iron in comparison to males. This decreases to approximately 60 ppm in the first 6 months of life, while the baby consumes an iron-deficient milk diet. Infants consuming cow milk have a greater incidence of iron deficiency because bovine milk has a higher concentration of calcium, which competes with iron for absorption. Subsequently, growing children must obtain approximately 0.5 mg more iron daily than is lost in order to maintain a normal body concentration of 60 ppm. During adult life, equilibrium between body loss and gain is maintained.
Children are more likely to develop iron deficiency anemia.
In certain geographic areas, hookworm adds to the problem. Children are more likely to walk in soil without shoes and develop heavy infestations. During childbearing years, women have a high incidence of iron deficiency anemia because of iron losses sustained with pregnancies and menses. Gastrointestinal neoplasms become increasingly more prevalent with each decade of life. They frequently present with gastrointestinal bleeding that may remain occult for long intervals before it is detected.