Fortification of food with
micronutrients such as
vitamins and minerals is one of the main strategies used to combat
micronutrient deficiencies. Fortification in common
salt is a fruitful strategy because of the daily consumption of 5-12 g
salt per person globally. Therefore double fortification of
salt with
iodine and
iron could be a reasonable approach to prevent both
iodine and
iron deficiencies. It is reckoned that about two billion people are
iodine-deficient worldwide.
Iodine deficiency during pregnancy may affect the health status of both mother and fetus and increase infant mortality. Deficiencies of both these
micronutrients during childhood affect somatic growth and cognitive and neurological function. Thyroid metabolism is negatively affected by
iron deficiency and reduced effectiveness of
iodine prophylaxis in areas of
endemic goiter. High prevalence of
iron deficiency among children may be reduced by the application of effective
iodized salt programs. However, ensuring the stability and bioavailability of both
iron and
iodine as double-fortified
salt is difficult.
Iodine present in
iodide or
iodate form in dual-fortified
salt is oxidized to free
iodine in the presence of ferrous
ions and
oxygen and consequently loses its characteristics. Moreover, ferrous
iron is more bioavailable but is readily oxidized to the less bioavailable ferric form. However, both forms of
iron may lead to discoloration of the final product, which can be reduced by providing a physical barrier around the
iron.
Salt encapsulation is one of the best tools to provide a physical barrier for undesirable reactions and interactions during storage. In this review the concept of dual
salt fortification, the impact of fortification on curing various life-threatening maladies, latest assessments of
mineral deficiencies and the choice of fortificants are discussed.