Until the nineteenth century, unspecified chronic anemia was known as chlorosis, or the “green sickness,” referring to the extreme pallor that characterized severe cases. For centuries, “chlorosis, or green sick-Dutch painters portrayed the pale olive complexion of chlorosis in portraits of young women” (Farley and Foland 1990: 89). Although such extreme cases are not common in Western societies today, less severe acquired anemia is quite common. In fact, acquired anemia is one of the most prevalent health conditions in modern populations.

Technically, anemia is defined as a subnormal number of red blood cells per cubic millimeter (cu mm), subnormal amount of hemoglobin in 100 milliliter (ml) of blood, or subnormal volume of packed red blood cells per 100 ml of blood, although other indices are usually also used. Rather than imputing anemia to unrequited love, modern medicine generally imputes it to poor diets that fail to replenish iron loss resulting from rapid growth during childhood, from menstruation, from pregnancy, from injury, or from hemolysis. One of today’s solutions to the frequency of acquired anemia is to increase dietary intake of iron. This is accomplished by indiscriminate and massive iron fortification of many cereal products, as well as the use of prescription and nonprescription iron supplements, often incorporated in vitamin pills. However, a nutritional etiology of anemia as dietary has, in the past, been assumed more often than proven. Determining such an etiology is complicated by the fact that the hematological presentation of dietary-induced iron deficiency anemia resembles the anemia of chronic disease. Of the many types and causes of acquired anemia, only those associated with diet and chronic disease are discussed here (for an overview of others, see Kent and Stuart-Macadam this volume).