Regular Consumption of a High-Phytate Diet Reduces the Inhibitory Effect of Phytate on Nonheme-Iron Absorption in Women with Suboptimal Iron Stores

J Nutr. 2015 Aug;145(8):1735-9. doi: 10.3945/jn.114.209957. Epub 2015 Jun 3.


Background: High phytate (HP) consumption is a concern in developing countries because of the high prevalence of iron deficiency in these countries.

Objective: We investigated whether habitual consumption of an HP diet reduces the inhibitory effect of phytate on nonheme-iron absorption.

Methods: Thirty-two nonanemic females, 18-35 y of age, with normal body mass index but with suboptimal iron stores (serum ferritin, ≤30 μg/L), were matched for serum ferritin concentration and randomly assigned to HP and low-phytate (LP) groups, in a parallel design study. Each subject consumed HP or LP foods with at least 2 of their daily meals for 8 wk, resulting in a change in phytate intake (from 718 to 1190 mg/d in the HP group and 623 to 385 mg/d in the LP group). The serum iron response over 4 h after a test meal containing 350 mg of phytate was measured at baseline and postintervention. Ferritin, transferrin receptor, and hepcidin concentrations were measured at baseline and 8 wk.

Results: Twenty-eight subjects completed the study (n = 14 per group). The serum iron response to the test meal increased in the HP group at postintervention, resulting in a 41% increase in the area under the curve (AUC; P < 0.0001). However, no effect was observed in the LP group (21% decrease in AUC; P = 0.76). The postintervention serum iron response was lower (P < 0.0001) in the LP group than in the HP group after controlling for the baseline serum iron response and hepcidin concentration, reflecting in a 64% lower AUC.

Conclusions: We found that habitual consumption of an HP diet can reduce the negative effect of phytate on nonheme-iron absorption among young women with suboptimal iron stores. Future studies are needed to explore possible mechanisms. This trial was registered at as NCT02370940.

Keywords: hepcidin; iron bioavailability; iron status; phytate; serum iron curve.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Biological Availability
  • Diet*
  • Female
  • Ferritins / blood
  • Hepcidins / blood
  • Humans
  • Iron / metabolism*
  • Iron, Dietary / administration & dosage
  • Iron, Dietary / pharmacokinetics
  • Phytic Acid / administration & dosage*
  • Phytic Acid / pharmacology*
  • Receptors, Transferrin / blood
  • Young Adult


  • Hepcidins
  • Iron, Dietary
  • Receptors, Transferrin
  • Phytic Acid
  • Ferritins
  • Iron

Associated data