Absorption of Zinc (Zn) From Zn-biofortified and Zn-fortified Maize in Young Zambian Children Between 24-36 Months

Study Overview
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Brief Summary
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The objective of this study is to compare the quantity of Zn absorbed from an accurately weighed quantity ( 100 g) of minimally milled control maize ( 15 µg Zn/g maize), from biofortified maize ( 30 µg Zn/g) and from the same control maize that has been fortified (total level of  60 µg Zn/g) when fed to young children age 24-36 months whose major habitual food staple is maize.

Detailed Description
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Participating children were randomized to receive an accurately weighed quantity of  100g/day of either the control, fortified or biofortified study maize for 1 day. On day 1, mothers brought their child to the health center before breakfast. All meals were extrinsically labeled with a zinc stable isotope (70Zn). Meals on this day were consumed in the presence of the research staff. The quantities of nshima or porridge prepared and eaten were accurately weighed and duplicate meals were collected for subsequent mineral analyses. Between lunch and dinner on day 1 at the Health Center, a blood sample was collected for Hb and plasma Zn analyses and, immediately after and through the same needle, a stable isotope of zinc was intravenously administered into a forearm vein over 1-2 minutes. The family then returned home. Morning spot urine samples were collected twice daily starting on day 5 and continuing through day 8. Once these collections were finished, the study for this child was complete. Dietary Zn was measured from laboratory assays of the duplicate test meals. Fractional absorption of Zn (FAZ) was measured by dual isotope tracer ratio methods in urine. Absorbed Zn was calculated by multiplying dietary Zn by FAZ.

Official Title
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Absorption of Zinc (Zn) From Zn-biofortified and Zn-fortified Maize in Young Zambian Children Between 24-36 Months

Conditions
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Nutritional Deficiency

Intervention / Treatment
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* Other: Biofortified Maize
* Other: Fortified Maize
* Other: Control Maize


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Children age 24 to 36 months Maize meal accounts for at least 75% energy intake Able to consume 100 g maize flour/day Clinically healthy (stunting is acceptable) Lives in target community Exclusion Criteria: Children with chronic or other known chronic disease If children are receiving zinc-fortified products, these products will need to be withheld for 2 weeks prior to the study

Ages Eligible for Study
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Minimum Age: 24 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: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Biofortified Maize<br>Participants in this arm were fed zinc biofortified maize ( 30 µg Zn/g). | Other: Biofortified Maize<br>* Participant in this arm were fed zinc biofortified maize ( 30 µg Zn/g).<br>|
| Experimental: Fortified Maize<br>Participants in this arm were fed zinc-oxide fortified maize (total level of  60 µg Zn/g). | Other: Fortified Maize<br>* Participants in this arm were fed zinc-oxide fortified maize (total level of  60 µg Zn/g).<br>|
| Active Comparator: Control Maize<br>Participants in this arm were fed maize that was not fortified or biofortified ( 15 µg Zn/g maize). | Other: Control Maize<br>* Participants in this arm were fed maize that was not fortified or biofortified ( 15 µg Zn/g maize).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Absorption of zinc | Absorption of zinc will be measured in young children fed a diet of control, Zn-biofortified, or Zn-fortified maize. Fractional absorption of zinc from all meals of the 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). | 1 day | 

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