Zinc Bioavailability From Amaranth-enriched Maize Tortillas

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


Lead Sponsor: University of Colorado, Denver

Collaborator: International Atomic Energy Agency
Universidad Francisco Marroquín

Source University of Colorado, Denver
Brief Summary

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

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.

Overall Status Completed
Start Date 2012-01-01
Completion Date 2015-12-01
Primary Completion Date 2015-12-01
Phase N/A
Study Type Interventional
Primary Outcome
Measure Time Frame
Zinc Absorption 2 days
Enrollment 20

Intervention Type: Other

Intervention Name: Day 1: Maize Tortillas with 20% Amaranth

Description: Subjects received Maize tortillas with 20% Amaranth added.

Arm Group Label: Maize Tortillas with 20% Amaranth

Intervention Type: Other

Intervention Name: Day 2 Maize Tortillas without 20% Amaranth

Description: Maize tortillas without Amaranth.

Arm Group Label: Maize Tortillas without 20% Amaranth



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



Minimum Age:

18 Months

Maximum Age:

36 Months

Healthy Volunteers:

Accepts Healthy Volunteers

Overall Official
Last Name Role Affiliation
Michael Hambidge, MD Principal Investigator University of Colorado, Denver
University of Colorado Anschutz Medical Campus | Aurora, Colorado, 80045, United States
Universidad Francisco Marroquin | Guatemala City, Guatemala
Location Countries


United States

Verification Date


Responsible Party

Type: Sponsor

Has Expanded Access No
Condition Browse
Number Of Arms 2
Arm Group

Label: Maize Tortillas with 20% Amaranth

Type: Experimental

Description: Children in this arm were fed maize tortillas fortified with 20% amaranth

Label: Maize Tortillas without 20% Amaranth

Type: Experimental

Description: Children in this arm were fed maize tortillas without amaranth

Patient Data No
Study Design Info

Allocation: Randomized

Intervention Model: Crossover Assignment

Masking: Single (Outcomes Assessor)

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