Relative bioavailability of iron and folic acid from a new powdered supplement compared to a traditional tablet in pregnant women.
BACKGROUND
Deficiencies of iron and folic acid during pregnancy can lead to adverse outcomes for the fetus, thus supplements are recommended. Adherence to current tablet-based supplements is documented to be poor. Recently a powdered form of micronutrients has been developed which may decrease side-effects and thus improve adherence. However, before testing the efficacy of the supplement as an alternate choice for supplementation during pregnancy, the bioavailability of the iron needs to be determined. Our objective was to measure the relative bioavailability of iron and folic acid from a powdered supplement that can be sprinkled on semi-solid foods or beverages versus a traditional tablet supplement in pregnant women.


METHODS
Eighteen healthy pregnant women (24 - 32 weeks gestation) were randomized to receive the supplements in a crossover design. Following ingestion of each supplement, the changes (over baseline) in serum iron and folate over 8 hours were determined. The powdered supplement contained 30 mg of iron as micronized dispersible ferric pyrophosphate with an emulsifier coating and 600 mug folic acid; the tablet contained 27 mg iron from ferrous fumarate and 1000 mug folic acid.


RESULTS
Overall absorption of iron from the powdered supplement was significantly lower than the tablet (p = 0.003). There was no difference in the overall absorption of folic acid between supplements. Based on the differences in the area under the curve and doses, the relative bioavailability of iron from powdered supplement was lower than from the tablet (0.22).


CONCLUSIONS
The unexpected lower bioavailability of iron from the powdered supplement is contrary to previously published reports. However, since pills and capsules are known to be poorly accepted by some women during pregnancy, it is reasonable to continue to explore alternative micronutrient delivery systems and forms of iron for this purpose.


BACKGROUND
ClinicalTrials.gov NCT00789490.
Hartman-Craven
Brenda
B
Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Canada. brenda.hartmancraven@sickkids.ca
Christofides
Anna
A
O'Connor
Deborah L
DL
Zlotkin
Stanley
S
D000293:Adolescent; D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000517:prevention & control*; D001682:Biological Availability; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004359:Drug Therapy, Combination; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D006397:Hematinics / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006801:Humans; D007501:Iron / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D011208:Powders; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000097:blood / Q000517:prevention & control*; D014131:Trace Elements / Q000008:administration & dosage / Q000493:pharmacokinetics*; D016896:Treatment Outcome; D055815:Young Adult
D006397:Hematinics; D011208:Powders; D014131:Trace Elements; D005492:Folic Acid; D007501:Iron