Etiology of hypoferremia in a recently sedentary Kalahari village.

To determine the etiology of hypoferremia in recently sedentary hunter-gatherers, a community located in the Kalahari Desert of Botswana was studied. Iron profiles of 106 Basarwa (Bushmen, San) volunteers were examined. Hematocrits were measured in the field. The remaining blood was processed for transportation to a research medical laboratory for further studies. Subnormal serum iron values were present, depending on the subpopulation, in 50-52% of the volunteers. Transferrin saturation was subnormal in 35-49% of those tested. The absence of subnormal serum ferritin levels indicates that dietary iron deficiency is not the cause of the hypoferremia. Instead, serum ferritin was greater than 50 micrograms/l (a level indicative of anemia of chronic disease/inflammation) in 92% of the hypoferremic adult Basarwa. We suggest that by depriving microbes of needed iron, the frequency of the anemia of infections and chronic disease in this population might be a response to, and defense against, a chronically high pathogen load in a community that has not yet incorporated sanitation practices appropriate for sedentary aggregations.