Inclusion of guava enhances non-heme iron bioavailability but not fractional zinc absorption from a rice-based meal in adolescents

J Nutr. 2013 Jun;143(6):852-8. doi: 10.3945/jn.112.171702. Epub 2013 Apr 17.

Abstract

Assessing the bioavailability of non-heme iron and zinc is essential for recommending diets that meet the increased growth-related demand for these nutrients. We studied the bioavailability of iron and zinc from a rice-based meal in 16 adolescent boys and girls, 13-15 y of age, from 2 government-run residential schools. Participants were given a standardized rice meal (regular) and the same meal with 100 g of guava fruit (modified) with (57)Fe on 2 consecutive days. A single oral dose of (58)Fe in orange juice was given at a separate time as a reference dose. Zinc absorption was assessed by using (70)Zn, administered intravenously, and (67)Zn given orally with meals. The mean hemoglobin concentration was similar in girls (129 ± 7.8 g/L) and boys (126 ± 7.1 g/L). There were no sex differences in the indicators of iron and zinc status except for a higher hepcidin concentration in boys (P < 0.05). The regular and modified meals were similar in total iron (10-13 mg/meal) and zinc (2.7 mg/meal) content. The molar ratio of iron to phytic acid was >1:1, but the modified diet had 20 times greater ascorbic acid content. The absorption of (57)Fe from the modified meal, compared with regular meal, was significantly (P < 0.05) greater in both girls (23.9 ± 11.2 vs. 9.7 ± 6.5%) and boys (19.2 ± 8.4 vs. 8.6 ± 4.1%). Fractional zinc absorption was similar between the regular and modified meals in both sexes. Hepcidin was found to be a significant predictor of iron absorption (standardized β = -0.63, P = 0.001, R(2) = 0.40) from the reference dose. There was no significant effect of sex on iron and zinc bioavailability from meals. We conclude that simultaneous ingestion of guava fruit with a habitual rice-based meal enhances iron bioavailability in adolescents.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorption
  • Adolescent
  • Antimicrobial Cationic Peptides / blood
  • Biological Availability
  • Diet
  • Female
  • Fruit*
  • Hemoglobins / analysis
  • Hepcidins
  • Humans
  • Iron Isotopes
  • Iron, Dietary / pharmacokinetics*
  • Male
  • Nutritional Status
  • Oryza / chemistry*
  • Psidium*
  • Sex Factors
  • Zinc / pharmacokinetics*
  • Zinc Isotopes

Substances

  • Antimicrobial Cationic Peptides
  • HAMP protein, human
  • Hemoglobins
  • Hepcidins
  • Iron Isotopes
  • Iron, Dietary
  • Zinc Isotopes
  • Zinc