Statistical methods. Characteristics of study children at baseline and at 5 and 12 months and the socioeconomic status of their families were compared between intervention groups using t-test on continuous variables and Ji2 for categorical variables (24). Distributions which were not normal were transformed and were compared using t-test. When adequate transformations were not achieved, the Wilcoxon Rank-sum test was employed (24. Intervention effects at 6 and 12 moths were assessed using General Linear Mixed Models with three repeated measures (25). Dependent variables were the prevalences of anemia or iron deficiency by either SF or sTfR. The interaction term between intervention and indicator variables for 6 and 12 months were used as the measure of effects at 6 and 12 months adjusting for baseline measurements. All models were adjusted for cluster effects (Milk Distribution Centers) and covariates. Adjusted probabilities were obtained to illustrate effects in graphic form26. Main effects were considered statistically significant at p values < 0.05 and interactions at p values <0.10. Statistical analyses were carried out using STATA (version 9.0)