sentences:  Additional vitamin-mineral supplementation may have an effect also in the developed world.A study giving such supplementation to "working class," primarily Hispanic, 6–12-year-old children in the United States for 3 months found an average increase of 2 to 3 IQ points.Most of this can be explained by the very large increase of a subgroup of the children, presumably because these were not adequately nourished unlike the majority.