[Iron and zinc supplementation during pregnancy: interactions and requirements].

The metabolism of iron and zinc during pregnancy is reported; their deficiency impairs foetal growth, and increases the rate of complications at delivery and of preterm births. Providing iron and zinc supplements must take into account their metabolic interactions which are likely to decrease their bioavailability. Supplementations should be prescribed only during at risk pregnancy and their dosage should be adapted to lessen these side effects and improve their efficiency.