Estimating the cost and cost-effectiveness of adding zinc to, and improving the performance of, Burkina Faso's mandatory wheat flour fortification programme.

Zinc is an essential micronutrient that promotes normal growth, development and immune function. In the context of persistent dietary zinc inadequacies, large-scale food fortification can help fill the gap between intake and requirements. Burkina Faso mandates wheat flour fortification with iron and folic acid. We used activity-based cost modelling to estimate the cost of adding zinc to the country's wheat flour fortification standard assuming (1) no change in compliance with the national standard, and (2) a substantial improvement in compliance. We used household food consumption data to model effective coverage, that is, the number of women of reproductive age (WRA) predicted to achieve adequate zinc density (zinc intake/1000 kcal) with the addition of fortification to diets. Without interventions, the prevalence of inadequate dietary zinc density was ~35.5%. With no change in compliance, the annual average incremental cost of adding zinc to fortified wheat flour was $10,347, which would effectively cover <1% of WRA at an incremental cost of ~$0.54/WRA effectively covered. Improving compliance added ~$300,000/year to the cost of the fortification programme without zinc; including zinc added another ~$78,000/year but only reduced inadequate intake among WRA by 3.6% at an incremental cost of ~$0.45/WRA effectively covered. Although the incremental cost of adding zinc to wheat flour is low ($0.01/wheat flour consumer/year), given low levels of wheat flour consumption, zinc fortification of wheat flour alone contributes marginally to, but will not fully close, the dietary zinc gap. Future research should explore potential contributions of zinc to a broader set of delivery vehicles.