Dietary factors affecting trace element bioavailability from human milk, cow's milk and infant formulas.

Bioavailability of trace elements is affected by the type of diet in which they are presented. In general, absorption of the elements iron, zinc, copper, manganese and selenium appears to be higher from human milk than from cow's milk or cow's milk formula while absorption from soy formula appears to be lower than from milk-based products. The effects of individual components such as protein source, carbohydrate, phytate, organic acids and other cations on absorption need to be assessed and the integrated effects of individual dietary components need to be assessed in the intact diet. While ideally absorptive studies should be performed in human infants, there is a need for developing useful and valid models for assessing trace element bioavailability. Increased knowledge about trace element absorption from different infant diets and the factors involved will lead to a better understanding of trace element requirements of infants. This will help in the suggestion of ways to improve means of supplementation.