We conducted a systematic review to determine the effectiveness of large-scale food fortification (LSFF) efforts on improving status and functional outcomes in low- and middle-income countries (LMICs). We also performed a qualitative review of the contextual factors that contribute to effective implementation of programs.
All applicable published and unpublished evidence was systematically retrieved and analyzed. There was no age restriction. Meta-analyses were performed for quantitative outcomes and results were presented as risk ratios (RR), odds ratios (OR), or standard mean differences (SMD) and 95% confidence intervals (CI). The WHO/CDC logic model for micronutrient interventions guided the assessment of program components.
LSFF increased relevant serum micronutrient concentrations in women and children of various age ranges and demonstrated a positive impact on functional outcomes, including anemia [risk ratio (RR): 0.64 (95% CI: 0.54, 0.75)], goiter [RR: 0.57 (95% CI: 0.41, 0.79)], and neural tube defects [RR: 0.62 (95% CI: 0.51, 0.75)]. We noted an age-specific effect of fortification, with a clear gradient towards higher impact among older women (>18 years) that potentially relates to intake and micronutrient dosage. There is a wide variation in quality of fortified foods against national fortification standards, relating to poor quality control/assurance in LMICs.
We have demonstrated a positive impact of LSFF programs in LMICs, showing measurable improvements in the micronutrient and health status of both women and children. However, the effective delivery of programs varies widely. Improving quality and ensuring access among those with risk of inadequate dietary intakes of micronutrients remains a significant priority.