After controlling for self-selection bias, participation in the WIC program (Special Supplemental Nutrition Program for Women, Infants, and Children) has a significant positive effect on children's intakes of iron, folate, and vitamin B-6. Iron is one of the five nutrients targeted by the program, the others being protein, calcium, vitamin A, and vitamin C. Folate and vitamin B-6, along with zinc, were recommended by a 1991 USDA study as nutrients that the program should also target. The data set used, the 1994-96 Continuing Survey of Food Intake by Individuals, reflects the dramatic increase during the 1990's in the number of children in the program.