Approaches to improve iron bioavailability from complementary foods.

The importance of trace element bioavailability in the etiology of nutritional deficiencies, for example in the etiology of iron deficiency and iron deficiency anemia, can be expected to be most pronounced in individuals with high requirements. Of special concern is the situation in poor communities where infants and young children are consuming monotonous, cereal-based diets. Traditionally, cereal-based gruels are often one of the first semisolid foods to be introduced into the infant's diet. These foods can be expected to have low energy and nutrient density as well as low bioavailability of iron due to the presence of phytic acid. Ascorbic acid is a potent enhancer of non-heme iron absorption that can overcome the inhibiting effect of phytic acid when present in high enough quantities. However, home prepared complementary foods based on cereals and legumes contain negligible amounts of ascorbic acid unless ascorbic acid-rich foods are mixed with the cereal or consumed at the same time. Different approaches to improve iron bioavailability from plant-based complementary foods, e.g., by enzymatic degradation of phytic acid and/or by increased consumption of ascorbic acid-rich foods, should be explored and adapted to local conditions. In addition, there is a need to evaluate efficacy and effectiveness of strategies to increase the dietary intake of bioavailable iron by dietary diversification and food fortification under realistic conditions.