Adjusted changes in mean hemoglobin differences by cumulative IFA tablets consumed over 1 school year among adolescent schoolgirls in the Northern and Volta regions of Ghana (n = 1307). Follow-up occurred 9 months after baseline. Estimates are weighted to be representative of all eligible girls in the school. Estimates and P values are calculated from generalized mixed models using maximum likelihood estimation, and accounted for clustering in school and intra-individual covariance. Adjusted for demographics, school level and geography, health characteristics, and diet. P value for trend = 0.029. Abbreviation: IFA, iron and folic acid.