Twice the recommended daily allowance of iron is associated with an increase in plasma α-1 antichymotrypsin concentrations in Guatemalan school-aged children

Abstract

The effects of iron on zinc status, oxidative stress, and inflammation were assessed in a randomized placebo-controlled trial; 66 children aged 8 to 11 years received iron (20 mg/d of elemental iron), zinc (42.5 mg/d of elemental zinc), or iron and zinc combined (20 and 42.5 mg/d, respectively) for 8 weeks. Hemoglobin, plasma ferritin (FT), and zinc concentrations were determined, and oxidative stress was based on plasma α-tocopherol, β-carotene, and thiobarbituric acid–reactive substance. Inflammation was based on increased α-1 acid glycoprotein, C-reactive protein, and α-1 antichymotrypsin (ACT) concentrations. At baseline, 19% of children were iron deficient (FT < 20 μg/L) and 69% had hypozincemia (zinc < 10.7 μmol/L) being distributed equally among the groups. Supplementation with iron or zinc alone improved, respectively, plasma FT or zinc concentrations (2-factor analysis of covariance, P ≤ .03), but no treatment interactions were found. Although none of the supplementation strategies was associated with oxidative stress or inflammation (2-factor analysis of covariance, P > .05), ACT concentrations increased with iron alone compared with the other supplementation strategies (median test, P < .01). The increase in ACT may represent a marker of peripheral activated oxidative stress; thus, twice the recommended daily allowance of iron alone warrants concern in augmenting reactive low-molecular-mass iron in nonanemic populations, although combination with zinc may mitigate this phenomenon.