DELIBERATIONS AND EVALUATIONS OF THE APPROACHES, END-POINTS AND PARADIGMS FOR IRON DIETARY RECOMMENDATIONS

Iron deficiency severe enough to cause anemia is associated with signi ficant morbidity while uncontrolled iron absorption which occurs in di sorders such as hereditary hemochromatosis causes multiorgan failure a nd early death. Preliminary data from the Third National Health and Nu trition Examination Survey demonstrate that the prevalence of iron def iciency anemia in the United States is now very low. This implies that the current iron consumption is adequate for most individuals. An imp ortant unresolved question relates to the necessity for further reduci ng the prevalence of iron deficiency without anemia. More information is required to determine whether this lesser degree of iron deficiency is harmful. Recent survey data indicate that concomitantly with the r educed prevalence of iron deficiency there has been a rise in serum fe rritin concentrations in American men and postmenopausal women. These findings have led to concern about the effectiveness of the physiologi cal mechanisms for limiting storage accumulation in normal individuals and carriers of the hemochromatosis gene when dietary iron content is high. Furthermore, recent epidemiological observations suggest that a modest increase in iron stores (in a range previously considered safe ) is a possible risk factor for ischemic heart disease and cancer; how ever, a causal relationship remains to be proven. Nonetheless, because there is no known benefit of high iron storage status, it seems prude nt to avoid further increases in and possibly to reduce the dietary ir on intake of men and postmenopausal women. Mean intake in these groups exceeds the current RDA by a significant margin. Therefore, the sourc es of dietary iron as well as other factors contributing to high serum ferritin values have to be defined. Also, efforts should be made to i ncrease the awareness of professionals and the public about the possib le risks of excessive dietary iron. The complexity of the Western diet and an incomplete understanding of all of the factors affecting serum ferritin concentrations make it very difficult to specify a safe uppe r range for daily iron intake at the present time.