ABSTRACT
Objectives: Zinc biofortification may be a sustainable way to improve Zn status, but questions remain on Zn bioavailability. We produced a novel biofortified wheat by Zn foliar application, and a separate wheat cultivar was intrinsically labeled with a Zn stable isotope. Goals were: a) To compare fractional and total Zn absorption (FAZ-TAZ) from chapattis prepared with biofortified, regular and postharvest fortified wheat; b) Compare the absorption of intrinsically and extrinsically Zn labels from biofortified wheat. Methods: Chapattis were prepared from flours with 100% and 80% extraction rates (ER). Meals were administered to 2 women's groups (N=44) in randomized order. Bioavailability was measured with double isotopic urinary technique with stable isotopes; four-day urines were collected and isotopic enrichment measured. Results: Foliar Zn application resulted in an increase of 45.6% of grain Zn. The control and biofortified wheat contained 25±0.12 ppm and 46±1.37 ppm Zn and 0.830±0.04 g/100 g and 0.807 ±0.03 g/100 g PA. The Zn:PA molar ratio for the unfortified, fortified and biofortified meals were 36, 63, 63 (100% ER) and 40, 67, 67 (80% ER). Mean total Zn in the intrinsically labeled wheat was 19.9±1.6 ppm. FAZ-TAZ data from the absorption studies are being analyzed. Conclusions: Foliar application increased Zn concentration without significantly changing PA concentration, and extraction rate is a determinant of the Zn:PA ratio. Assessment of FAZ-TAZ will provide: a) Data on the potential of foliar zinc biofortified wheat, and b) proof that the double isotope technique used to assess absorption of extrinsic Zn labels in biofortified wheat is valid.
ABSTRACT
Objectives: In sub-Saharan Africa, parasitic diseases and low intake of bioavailable iron are the main causes of anemia. Anemia is further increased by inflammation during malarial infections blocking iron recycling and decreasing iron absorption. The influence of hookworm and Schistosoma infections on iron absorption and recycling is not known. Our objectives were to compare the influence of malaria, hookworm, and Schistosoma infections on inflammation, iron absorption and iron incorporation. Methods: Ivorian adolescents (12-17 years) presenting with a single infection of afebrile P. falciparum, hookworm or S. haematobium consumed 200 mL of test syrup containing 3 mg iron as ferrous sulfate labeled with 57Fe. Fractional absorption of the stable iron isotope was measured during infection and two weeks after treatment when subjects were free of infection. Erythrocyte incorporation of intravenous iron labeled with 58Fe and inflammation biomarkers were also measured. Results: Geometric mean iron absorption was 12.1% (95% CI: 9.2 - 18.0) during afebrile P. falciparum infection and increased to 23.6% (95% CI: 19.6 - 28.5) (P < 0.05) after treatment. Inflammation biomarkers were elevated during malarial infection and decreased after treatment. Light to moderate hookworm and S. haematobium infections did not increase inflammation and did not influence iron absorption (P > 0.05). Erythrocyte incorporation of intravenous iron was not affected by P. falciparum, hookworm or S. haematobium infections (P > 0.05). Conclusions: Unlike afebrile P. falciparum infection, light to moderate hookworm and S. haematobium infections do not lead to low-grade inflammation, and do not decrease iron absorption.