[영문]ObjectivesTo assess the effectiveness of home visits advising mothers about breast feeding and weaning in reducing symptoms of respiratory morbidity at the age of 12 months.MethodsA randomized field trial was conducted with mothers who gave birth within the public health system in the Brazilian city of Sao Leopoldo (2001/2002). The intervention group received dietary advice during the first year based on a Brazilian national health policy for primary care, which is based on WHO guidelines. Morbidity data was assessed in 397 children at 12 months.ResultsA total of 23.3% of the children in the intervention group and 39.7% of the controls had one or more of the following symptoms during the month preceding assessment: cough, stuffy nose, runny nose, or breathlessness. The risk of respiratory morbidity symptoms was 41% lower for the intervention group (RR: 0.59; 95% CI: 0.43?0.81). The number of families needed to be visited to avoid one children presenting symptoms of respiratory morbidity (Number Needed to Treat) was 6.1. The intervention-group status was also associated with a longer duration of exclusive (RR:1.59; 95% CI: 1.21?2.07; p = 0.001) and total breastfeeding (RR: 1.25; 95% CI:1.02?1.55; p = 0.032) later introduction of solid foods (RR:1.11; 95% CI: 1.02?1.21; p = 0.023), and a lower proportion of current medication use (RR:0.56; 95% CI:0.34?0.91;p = 0.016).ConclusionA nutrition education program during the first year of life has a positive impact on reducing respiratory symptoms in infants