Iron supplementation brings up a lacking P300 in iron deficient children

Objective: A decrease in iron concentration is accompanied by alterations in catecholaminergic and GABAergic neurotransmission systems, important in learning, memory and attention. It was hypothesized that iron deficient children would present attention deficits. A visual-event related potentials (ERPs) study is presented using an oddball paradigm in order to determine the P300 in ID children. Methods: After medical examination, blood was obtained from 201 children for a complete hematological study. Two groups were selected, iron deficient (ID) (serum iron <60 μg/dl) and control (C) (serum iron >60 μg/dl). In both groups ERPs were recorded while executing a continuous performance task (oddball paradigm). Afterwards iron levels were restored in ID children by iron supplementation (ID–IS group) and all tests reapplied. Results: ID children almost lacked a P300 in central and parietal regions. After iron supplementation, P300 clearly became evident although its Pz amplitude remained smaller compared to C children. Conclusions: A clear and strong correlation was found between ID and attention alterations in children. Iron supplementation nearly brings the P300 to normal levels although it is not known if the P300 difference in Pz is due to other nutritional/environmental deficits or to developmental psychomotor impairments in ID children. Significance: It has been long known that iron deficient children have cognitive impairments but there is an insufficient number of electrophysiological works allowing to identify the source of this problem. In this work an attention deficit is demonstrated in ID children through a severely reduced P300, which recovers substantially after iron supplementation.