Zinc AbsorptionNCT06650397
Guatemala Biofortified Maize Study
A study testing Biofortified maize in people with Zinc Absorption and Iron Absorption, run by University of Colorado, Denver at 1 site in Guatemala.
Trial summary
Zinc (Zn) and iron (Fe) deficiencies are common in Guatemala, and maize is a staple food throughout the country. The primary aim of this study is to demonstrate if utilizing nixtamalized biofortified maize has the potential to increase dietary Zn and Fe intake and improve the amount of Zn and Fe absorbed when compared… Read more about this study
- Who is it for?
- Ages 10 to 14 yearsHealthy volunteers can take part
- Conditions the study is for
- Zinc Absorption, Iron Absorption
- What is being tested?
- Biofortified maize
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 56 participants
- Where
- 1 siteGuatemala
- Study dates
- 31 Jul 2024to 28 Feb 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 10 to 14 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- 10-14 years old school children (male and female sex)
- BMI between10-85%tile
- Typically eat homemade tortillas at each meal every day
Who cannot join
- Taking iron or zinc supplements
- Hemoglobin less than 12.9 g/dl for children 10-11 yrs old and less than13.4 g/dl for children 12-14 yrs old (Per the WHO's 2024 publication hemoglobin cut-offs for identifying anemia are 5-11 yrs: less than 11.5 g/dl; 12-14 yrs: less than 12.0 g/dl. To adjust for the elevation of Tecpán at 2254 m, 1.4 g/dl is added to the cut-off point.)
- Girls who are having a menstrual period during the metabolic studies
Trial locations and contacts
1 site in 1 country.
Guatemala1 site
Institute of Nutrition of Central America and Panama
Guatemala City, Departamento de Guatemala, 1188
About this study
Official title: Absorption of Zinc and Iron From Nixtamalized Biofortified Maize in School-aged Children in Guatemala
Zinc (Zn) and iron (Fe) deficiencies are common in Guatemala, and maize is a staple food throughout the country. The primary aim of this study is to demonstrate if utilizing nixtamalized biofortified maize has the potential to increase dietary Zn and Fe intake and improve the amount of Zn and Fe absorbed when compared to diets incorporating traditional maize (control). This is a randomized, double blinded, comparison study of biofortified vs control maize prepared as tortillas from nixtamalized masa. This study will enroll up to 56 school aged children (10-14 yrs old) living in agricultural communities in the Western Highlands of Guatemala (28/group x 2 groups). Researchers will utilize Zn and Fe stable isotopes to measure total absorbed Zn and Fe. Participants will be active in the study for 27 days. During this time, they will have anthropometric measurements taken and collect 2 blood samples, 1 stool sample, and 9 urine samples.
- Conditions
- Zinc Absorption, Iron Absorption
- Being tested
- Biofortified maize, Placebo
- Keywords
- biofortification, stable isotope, maize, Guatemala, school-aged children
- Medical subject headings
- Callosities
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Biofortified maizeOther
Maize that has been grown to have higher amounts of iron and zinc.
PlaceboOther
Traditional maize
| Study group | Role | What they receive |
|---|---|---|
| Biofortified maize | Experimental | Children consume biofortified maize that has been traditionally bred to have higher amounts of iron and zinc. Children consume the biofortified maize via 10-15 tortillas a day for 3 days. Receives: Other: Biofortified maize |
| Traditional Maize | Placebo comparator | Children consume traditional maize that has lower amounts of iron and zinc compared to the biofortified maize. Children consume the maize via 10-15 tortillas a day for 3 days. Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Total absorbed iron (TAI) (mg)
Total absorbed iron from the diet = fractional absorption of iron x total dietary iron (mg)
Measured: 2 days
Total absorbed zinc (TAZ) (mg)
Total zinc absorbed from the diet = fractional absorption of zinc x total dietary zinc (mg)
Measured: 1 day
Secondary outcomes (3)
Plasma C-reactive protein (CRP) (mg/dL)
CRP is used to measure systemic inflammation
Measured: 1 day
Plasma zinc concentration (mcg/dL)
Plasma zinc concentration is used to assess zinc status
Measured: 1 day
Plasma Alpha(1)-acid glycoprotein (AGP) (mg/dL)
AGP is used to measure systemic inflammation
Measured: 1 day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Oct 2024
- Study start31 Jul 2024
- Primary completion28 Feb 2026
- Study completion28 Feb 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Zinc AbsorptionStudies of the same condition, open and under way.
- More trials run by University of Colorado, DenverThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 56 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Colorado, Denver
- Sponsor type
- University, hospital or other
- Collaborators
- Institute of Nutrition of Central America and Panama, Semilla Nueva
- Responsible party
- Sponsor
- Investigators
- Nancy F Krebs, MD, MS, Principal investigator, University of Colorado, Denver
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06650397
- Sponsor's protocol ID
- 24-1030
- Other IDs
- 7200AA23FA00027, 261570
- Status last verified
- May 2026
- First submitted
- 4 Sep 2024
- Last updated
- 8 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: A de-identified dataset will be made available upon request.
Study at a glance
From the registry record, last updated by the sponsor on 8 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Absorption of Zinc and Iron From Nixtamalized Biofortified Maize in School-aged Children in Guatemala
- ClinicalTrials.gov ID
- NCT06650397
- Acronym / sponsor ID
- 24-1030
- Conditions
- Zinc Absorption, Iron Absorption
- Keywords
- biofortification, stable isotope, maize, Guatemala, school-aged children
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 56 participants (actual)
- Lead sponsor
- University of Colorado, DenverUniversity, hospital or other
- Collaborators
- Institute of Nutrition of Central America and Panama, Semilla Nueva
- Study start
- 31 Jul 2024 (actual)
- Primary completion
- 28 Feb 2026 (actual)
- Study completion
- 28 Feb 2026 (actual)
- First posted
- 21 Oct 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Zinc (Zn) and iron (Fe) deficiencies are common in Guatemala, and maize is a staple food throughout the country. The primary aim of this study is to demonstrate if utilizing nixtamalized biofortified maize has the potential to increase dietary Zn and Fe intake and improve the amount of Zn and Fe absorbed when compared to diets incorporating traditional maize (control). This is a randomized, double blinded, comparison study of biofortified vs control maize prepared as tortillas from nixtamalized masa. This study will enroll up to 56 school aged children (10-14 yrs old) living in agricultural communities in the Western Highlands of Guatemala (28/group x 2 groups). Researchers will utilize Zn and Fe stable isotopes to measure total absorbed Zn and Fe. Participants will be active in the study for 27 days. During this time, they will have anthropometric measurements taken and collect 2 blood samples, 1 stool sample, and 9 urine samples.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Biofortified maize | Experimental | Other: Biofortified maizeChildren consume biofortified maize that has been traditionally bred to have higher amounts of iron and zinc. Children consume the biofortified maize via 10-15 tortillas a day for 3 days. |
| Traditional Maize | Placebo comparator | Other: PlaceboChildren consume traditional maize that has lower amounts of iron and zinc compared to the biofortified maize. Children consume the maize via 10-15 tortillas a day for 3 days. |
Who may qualify
- Ages
- 10 to 14 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (3 listed)
- 10-14 years old school children (male and female sex)
- BMI between10-85%tile
- Typically eat homemade tortillas at each meal every day
Key exclusion criteria (3 listed)
- Taking iron or zinc supplements
- Hemoglobin less than 12.9 g/dl for children 10-11 yrs old and less than13.4 g/dl for children 12-14 yrs old (Per the WHO's 2024 publication hemoglobin cut-offs for identifying anemia are 5-11 yrs: less than 11.5 g/dl; 12-14 yrs: less than 12.0 g/dl. To adjust for the elevation of Tecpán at 2254 m, 1.4 g/dl is added to the cut-off point.)
- Girls who are having a menstrual period during the metabolic studies
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Biofortified maizeMaize that has been grown to have higher amounts of iron and zinc. | Other | Biofortified maize |
| PlaceboTraditional maize | Other | Traditional Maize |
Primary outcome
Total absorbed iron (TAI) (mg)
Time frame: 2 days
Total absorbed iron from the diet = fractional absorption of iron x total dietary iron (mg)
Total absorbed zinc (TAZ) (mg)
Time frame: 1 day
Total zinc absorbed from the diet = fractional absorption of zinc x total dietary zinc (mg)
3 secondary outcomes
Plasma C-reactive protein (CRP) (mg/dL)
Time frame: 1 day
Plasma zinc concentration (mcg/dL)
Time frame: 1 day
Plasma Alpha(1)-acid glycoprotein (AGP) (mg/dL)
Time frame: 1 day
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 May 2026.
- Individual participant dataSharing planned: Undecided. A de-identified dataset will be made available upon request.
Related trials for Zinc Absorption
Recruiting
Zinc and Iron Absorption From Common Beans in Young Adult Women
Zinc Absorption, Iron Absorption
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Nancy F Krebs, MD, MS principal investigator
University of Colorado, Denver
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Biofortified maize in people with Zinc Absorption and Iron Absorption, run by University of Colorado, Denver at 1 site in Guatemala.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 8 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Guatemala. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Total absorbed iron (TAI) (mg) (time frame: 2 days). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 May 2026.