Abstract
Healthy persons probably maintain a positive iron balance by a narrower margin than was formerly believed. Approximately 5-10% of food iron seems to be assimilated by normal adults; daily retention on a diet containing 12-15 mg of iron, therefore, may be estimated to be about 0.6-1.5 mg. The amount of iron lost from the body each day in all ways except as blood seems to be between 0.5 and 1 mg. The added requirements of children and young women to compensate for growth needs and menstrual flow place them in a precarious state of iron balance so that poor diet or poor absorption can readily lead to the production of hypochromic anemia. In adult men or postmenopausal women, however, nutritional factors appear to be of less importance in the pathogenesis of iron-deficiency. If purely nutritional iron deficiency ever occurs in these people, many years would be required for its production. It is more likely that occult, intermittent bleeding, often difficult to detect, must also be present along with inadequate diet or malabsorption before severe degrees of iron deficiency develop.