Bioavailability of iron in two prenatal multivitamin/multimineral supplements.
OBJECTIVE
To determine the iron bioavailability in two popular prenatal multivitamin/multimineral supplement tablets containing 27 mg elemental iron.


METHODS
Iron absorption during an eight-hour period following ingestion of a multivitamin/multimineral formulation, both fasting and with a standardized meal, was measured in a group of 30 pregnant women (24-32 weeks of gestation) and statistically compared. The prenatal formulations were Stuartnatal Plus and Materna (Wyeth-Ayerst Pharmaceuticals, Philadelphia, Pennsylvania), and each contains 27 mg of elemental iron. A placebo was included in the study for the control group in this crossover, single-blind study.


RESULTS
The net iron bioavailability (mean +/- SE) of Stuartnatal Plus and Materna, accounting for diurnal variation, and the iron ingested with the standardized meal was 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, postprandially. 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.


CONCLUSIONS
The results of this study indicate that these two prenatal multivitamin/multimineral formulations provide > 3.0 mg of supplemental iron absorption (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.
Dawson
E B
EB
Department of Obstetrics and Gynecology, University of Texas Medical Branch at Galveston 77555-0587, USA. ebdawson@utmb.edu
Evans
D R
DR
McGanity
W J
WJ
Conway
M E
ME
Harrison
D D
DD
Torres-Cantu
F M
FM
D000328:Adult; D001682:Biological Availability; D018592:Cross-Over Studies; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007501:Iron / Q000097:blood / Q000493:pharmacokinetics*; D018673:Nutrition Policy; D011247:Pregnancy / Q000378:metabolism*; D012016:Reference Values; D016037:Single-Blind Method
D007501:Iron