A total of 321 South African children ( aged 6-11 y ) with iron deficiency ( ID ) were randomly divided into 4 groups to receive 1 ) iron plus placebo , 2 ) a mixture of docosahexaenoic acid and eicosapentaenoic acid ( DHA/EPA ) plus placebo , 3 ) iron plus DHA/EPA , or 4 ) placebo plus placebo as oral supplements 4 times/wk for 8.5 mo. .