Zinc Bioavailability From Amaranth-enriched Maize Tortillas

Study Overview
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Brief Summary
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Young children in Guatemala are at risk for nutrient deficiencies due to plant-based diets and poor sanitation. Stunting, frequent diarrhea, and respiratory infections are common. Supplementation of Zn to children during diarrhea episodes has been shown to diminish duration and severity of illness. Poor Zn absorption due to high fiber and phytate in this diet might play a role in these processes. Supplementation of this micronutrient in the diet might be beneficial. The investigators will compare absorption of Zn from white maize tortillas enriched with 20% amaranth to traditional white corn tortillas in preschool children in Guatemala.

Detailed Description
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This is a randomized cross-over study of zinc absorption in young children living in the Western Highlands of Guatemala. Absorption of zinc will be measured from maize tortillas and maize tortillas fortified with 20% amaranth as the major food staple which provides at least 70% energy and at least 90% zinc and phytate of the diet. Participants will be randomized as to which type of tortilla they receive on the first and second day. Fractional absorption of zinc (FAZ) from all meals in one day for one type of tortilla and one day for the other will be measured by extrinsic labeling with stable isotopes of zinc. FAZ will be measured by a dual isotope tracer ratio (DITR) technique based on ratio of urine enrichment of orally versus intravenously administered zinc stable isotopes. Measurement of total zinc in duplicate diets on test days allow for determination of quantities of this micronutrient absorbed.

Official Title
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Absorption of Zinc (Zn) From Traditional Maize Tortillas and Amaranth-enriched Tortillas by Toddlers in the Indigenous Post-Mayan Population

Conditions
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Nutritional Deficiency

Intervention / Treatment
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* Other: Day 1: Maize Tortillas with 20% Amaranth
* Other: Day 2 Maize Tortillas without 20% Amaranth


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 2-3 years of age apparently healthy eats >2-3 tortillas at each meal of the day. Exclusion Criteria: Chispitas or macrovital supplementation breastfeeding birth weight < 2,500 g birth defect affecting growth and development chronic infection twin or triplet sibling enrolled in study

Ages Eligible for Study
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Minimum Age: 18 Months
Maximum Age: 36 Months

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Maize Tortillas with 20% Amaranth<br>Children in this arm were fed maize tortillas fortified with 20% amaranth | Other: Day 1: Maize Tortillas with 20% Amaranth<br>* Subjects received Maize tortillas with 20% Amaranth added.<br>|
| Experimental: Maize Tortillas without 20% Amaranth<br>Children in this arm were fed maize tortillas without amaranth | Other: Day 2 Maize Tortillas without 20% Amaranth<br>* Maize tortillas without Amaranth.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Zinc Absorption | Absorption of zinc will be compared in young children when fed the common maize tortilla and a tortilla fortified with 20 % amaranth.. Fractional absorption of zinc for a day will be measured by extrinsic labeling with stable isotopes of zinc. Fractional absorption of zinc will be measured by a dual isotope tracer ratio technique. Measurement of total zinc in duplicate diets on test day will allow determination of quantity of this micronutrient absorbed (mg/d). | 2 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Maize, Zinc Absorption, Amaranth, Guatemala, Stable isotopes of Zn