Effects of Dietary Iron Intake on Immune Status in Male College Students

This study was performed to investigate the effect of dietary iron intake on the immune status of male college students. Twenty healthy male university students participated in the study. The mean age of the subjects was 22.6 years old, mean height was 173.3 cm and mean body weight was 68.4 kg. The mean daily iron intake of the subjects was 19.9 mg, 158.1% of the Korean recommended dietary allowances (RDA). The blood iron status and immune responses of the subjects were analyzed and compared between the high dietary iron group consuming more than 100% of the RDA of iron (Hi-Fe) and the low dietary iron group consuming less than 100% of the RDA of iron (Low-Fe). The serum iron concentration and percent saturation of transferrin were within the normal range in both groups. However, the Hi-fe group had higher serum iron and percent saturation of transferrin than the Low-fe group (p<0.05). When differential white blood cell counts were compared, the Low-Fe group had a lower percentage of neutrophils than the Hi-Fe group (p <0.1). The plasma IL-2 concentration, immunoglobulin levels and lymphocyte subsets were not affected significantly by the differences in iron intake as shown in this study. Serum iron had a positive correlation with monocyte percentage but had a negative correlation with IgM concentration. The results of this study suggest that slightly-low dietary iron intake without anemia has no effects on the cell-mediated and humoral immunities of healthy male university students. However, natural defenses, such as neutrophils and monocytes, seem to be more sensitively affected by changes in dietary iron intake.