Prenatal iron supplements impair zinc absorption in pregnant peruvian women

K. O. O'Brien, N. Zavaleta, L. E. Caulfield, J. Wen, S. A. Abrams

Research output: Contribution to journalArticlepeer-review

110 Scopus citations


Prenatal iron supplements may adversely influence zinc absorption during pregnancy. To examine the impact of prenatal iron supplements on supplemental zinc absorption, fractional zinc absorption was measured in 47 pregnant Peruvian women during the third trimester of pregnancy (33 ± 1 wk gestation). Of these 47 women, 30 received daily prenatal supplements from wk 10-24 of pregnancy until delivery. Supplements contained 60 mg of Fe and 250 μg of folate without [iron group (Fe), n = 16] or with [iron and zinc supplemented group (Fe + Zn), n = 14] 15 mg of Zn. The remaining 17 women [unsupplemented control group (C)] received no prenatal supplementation. Zinc concentrations were measured in plasma, urine and cord blood and percentage zinc absorption was determined following dosing with oral (67Zn) and intravenous (70Zn) stable zinc isotopes. Percentage zinc absorption was significantly lower than controls in fasting women receiving iron- containing prenatal supplements (20.5 ± 6.4 vs. 20.2 ± 4.6 vs. 47.0 ± 12.6%, Fe, Fe + Zn and C groups, respectively, P < 0.0001, n = 40). Plasma zinc concentrations were also significantly lower in the Fe group compared to the C group (8.2 ± 2.2 vs. 9.2 ± 2.2 vs. 10.9 ± 1.8 μmol/L, Fe, Fe + Zn and C groups, respectively, P = 0.002), and cord zinc concentrations were significantly related to maternal plasma Zn levels (y = 6.383 + 0.555x, r = 0.486, P = 0.002). The inclusion of zinc in prenatal supplements may reduce the potential for iron supplements to adversely influence zinc status in populations at risk for deficiency of both these nutrients.

Original languageEnglish (US)
Pages (from-to)2251-2255
Number of pages5
JournalJournal of Nutrition
Issue number9
StatePublished - 2000


  • Absorption
  • Iron
  • Peru
  • Pregnancy
  • Stable isotopes
  • Women
  • Zinc

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics


Dive into the research topics of 'Prenatal iron supplements impair zinc absorption in pregnant peruvian women'. Together they form a unique fingerprint.

Cite this