Iron supplementation increased the number of days with illness when all symptoms were considered ( B : 0.87 ; 95 % CI : 0.71 , 1.03 ) as well as illness that was specifically caused by respiratory symptoms ( B : 1.45 ; 95 % CI : 1.21 , 1.70 ) , whereas DHA/EPA reduced the number of days with illness at school ( B : -0.96 ; 95 % CI : -1.33 , -0.59 ) .