Bioavailability of iron in two multivitamin/multimineral supplements

OBJECTIVE: To determine the iron bioavailability in two popular prenatal mu ltivitamin/multimineral supplement tablets containing 27 mg elemental iron. STUDY DESIGN: Iron absorption during an eight-hour period following ingesti on of a multivitamin/multimineral formulation, both fasting and with a stan dardized meal, was measured in a group of 30 pregnant women (24-32 weeks of gestation) and statistically compared. The prenatal formulations were Stua rtnatal Plus(R) and Materna(R) (Wyeth-Ayerst Pharmaceuticals, Philadelphia, Pennsylvania), and each contains 27 mg of elemental iron. A placebo was in cluded in the study for the control group in this crossover, single-blind s tudy. RESULTS: The net iron bioavailability (mean +/- SE) of Stuartnatal Plus(R) and Materna(R), accounting for diurnal variation , and the iron ingested wi th the standnardized meal tons 5.4 +/- 0.4 and 4.6 +/- 0.2 mg, respectively , while fasting and 2.9 +/- 0.4 and 2.7 +/- 0.4 mg, respectively, postprand ially. The total amount of iron absorption in the fasting states from both prenatal formulations exceeded the 3 mg of supplemental iron absorption per day recommended by the National Academy of Sciences. CONCLUSION: The results of this study indicate that these two prenatal mult ivitamin/multimineral formulations provide > 3.0 mg of supplemental iron ab sorption (fasting) as recommended by the National Academy of Sciences and 2 .7 mg of iron absorption above the levels achieved following ingestion of a standard, low-iron test meal.