Evaluation of novel assessment tools and interventions to improve micronutrient nutrition (Guatemala)

Iron (Fe) and Zinc (Zn) deficiencies are the most prevalent mineral disorders in the world. Public health, nutrition and food-based interventions for iron deficiency anemia (IDA) have not been effective. One of the main limitations in this area has been the low bioavailability of the iron in food and in compounds used in food fortification to prevent IDA. Zinc deficiency (ZnD) remains a neglected public health problem principally because there is a lack of biomarkers for accurate detection of milder ZnD states and for measurement of the impact of interventions. To contribute to the available interventions against IDA, we assessed the bioavailability of soy bean root nodule (heme- and non-heme) iron using the hemoglobin repletion efficiency (HRE) assay in the anemic growing rat (Study 1), and soy-maize-wheat flour cookies fortified with bovine hemoglobin concentrate and multiple micronutrients in a community-based randomized controlled trial with non-pregnant iron-deficient Guatemalan women (study 2). Based on the behavior of urinary Zn excretion during Zn depletion studies, the response or urinary Zn excretion to Zn supplementation (0, 10, 20 mg Zn/d x 24 d) was studied as a potential indicator of recent population Zn intake (study 3). Results show that (1) soy root nodule iron is as bioavailable as standard ferrous sulfate and more efficiently utilized for hemoglobin synthesis than bovine hemoglobin by the rat model; (2) there is no significant effect of bovine hemoglobin concentrate iron or ferrous fumarate iron on iron status when these are consumed as fortificants of cookies that contain important amounts of iron absorption inhibitors, particularly, in the case of heme iron, because hemoglobin is denatured by heat during prolonged baking of cookies (50 minutes) at high temperature (325°C), and finally that (3) urinary zinc excretion does not parallel zinc intake when supplements containing 10-20 mg/d are given daily to a marginally Zn nourished population of healthy non-pregnant women.