Influence of different nano/micro-carriers on the bioavailability of iron: Focus on in vitro–in vivo studies

Anemia resulting from iron (Fe) deficiency is a global public health problem. The deficiency of Fe is usually due to insufficient dietary intake of iron, interaction of Fe with other food components, and thus low bioaccessibility/bioavailability. Fe encapsulation has the potential to tackle some major challenges in iron fortification of foods. Various nano/micro-carriers have been developed for encapsulation of Fe, including emulsions, liposomes, hydrogels, and spray-dried microcapsules. They could reduce the interactions of Fe with food components, increase iron tolerance and intestinal uptake, and decrease adverse effects. This article review covers the factors affecting the bioavailability of Fe along with emerging carriers that can be used as a solution of this issue. The application of Fe-loaded carriers in food supplements and products is also described. The advantages and limitations associated with the delivery efficiency of each carrier for Fe are highlighted.