Iron absorption from four prenatal multivitamin/multimineral preparations was compared in 36 healthy pregnant women in their second or third trimester of pregnancy. The products studied were the currently marketed formulations of Stuartnatal 1 + 1, Stuart Prenatal, Materna, and Natalins Rx. Each fasted subject received each of the four preparations, according to a randomized sequence, at intervals of three to seven days between drug administrations. Stuartnatal 1 + 1 demonstrated the best iron absorption. Total iron absorbed from Stuartnatal 1 + 1 and Stuart Prenatal was well above the additional daily 3.5 mg recommended during pregnancy. Following administration of Materna the amount of iron was only slightly above that recommended, and following Natalins Rx it was well below. All formulations were generally well tolerated by the subjects.