The Efficacy of Pro-vitamin A Biofortified Cassava on Vitamin A Status in Nigerian Preschool Children (CASSAVITA II)
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ClinicalTrials.gov Identifier: NCT02627222 |
Recruitment Status :
Completed
First Posted : December 10, 2015
Last Update Posted : February 5, 2020
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Condition or disease | Intervention/treatment | Phase |
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Vitamin A Deficiency | Other: Pro-vitamin A biofortified cassava Other: White cassava | Not Applicable |
Objective: The primary objective is to assess the efficacy of daily consumption of pro-vitamin A rich cassava during 10 weeks on body retinol pools of 3-4 year old children in Nigeria after high-dose vitamin A supplementation. The secondary objectives are: 1) To investigate the effect of daily consumption of pro-vitamin A rich cassava on functional indicators such as nutritional anaemia and gut integrity; 2) To investigate the effect of zinc deficiency and genetic polymorphisms in the Beta-Carotene Oxygenase 1 (BCO1) and related genes on the efficacy of pro-vitamin A rich cassava consumption; 3) To compare the skin colour in the palm of the hand of each participant with their serum retinol levels using a handheld non-invasive spectrophotometer.
Study design: Open-label (single-blinded) randomized controlled trial with two parallel groups Study population: Pre-school children, aged 3-4 years living in Osun State area, South-Western Nigeria. Children (n=750) will be screened for eligibility. Out of these, n=250 will undergo a 4-week run-in phase. n=200 children will be randomly allocated to two different treatments: 1) Yellow cassava providing ~50% of the recommended daily allowance (RDA) for vitamin A; 2) White cassava.
Main study parameters/endpoints: The primary outcome was the difference in body retinol pools between groups 1 and 2 at the end of intervention; however, due to the inability to assess body retinol pools, the modified primary outcome is the difference in serum retinol concentrations between groups 1 and 2. Other outcome measures include: other vitamin A status indicators (β-carotene, retinol binding protein, transthyretin), inflammatory markers, iron status indicators, anthropometrics, gut integrity, and thyroid function.
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 176 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Single (Outcomes Assessor) |
Primary Purpose: | Prevention |
Official Title: | The Efficacy of Pro-vitamin A Biofortified Cassava on Vitamin A Status in Nigerian Preschool Children |
Study Start Date : | December 2015 |
Actual Primary Completion Date : | May 2016 |
Actual Study Completion Date : | December 2016 |

Arm | Intervention/treatment |
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Active Comparator: Treatment
Daily consumption of two cassava-based meals prepared with pro-vitamin A rich biofortified cassava
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Other: Pro-vitamin A biofortified cassava
Pro-vitamin A biofortified cassava is the product of international conventional breeding programs (non-GMO) in order to increase the pro-vitamin A content of cassava for improved nutritional intake
Other Names:
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Placebo Comparator: Control
Daily consumption of two cassava-based meals prepared with common white cassava
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Other: White cassava
Conventional white cassava
Other Names:
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- Body retinol pool (omitted) [ Time Frame: 13 weeks ]Difference in body retinol pools between groups
- (Modified primary outcome): Serum retinol [ Time Frame: 13 weeks ]Difference in serum retinol pools between groups
- Anaemia [ Time Frame: 13 weeks ]Difference in haemoglobin concentration between groups
- Gut integrity [ Time Frame: 11 weeks ]Difference in gut integrity between groups
- Serum betacarotene [ Time Frame: 13 weeks ]Difference in serum retinol concentration between groups
- Retinol binding protein [ Time Frame: 13 weeks ]Difference in serum retinol binding protein concentration between groups
- Urinary thiocyanate [ Time Frame: 11 weeks ]Difference in urinary thiocyanate concentration between groups
- Thyroid function indicators [ Time Frame: 13 weeks ]Difference in serum thyroid function indicators between groups
- Serum zinc [ Time Frame: Baseline ]Effect modification by baseline zinc deficiency
- Genetic polymorphisms in the BCO1 gene [ Time Frame: Baseline ]Effect modification by BCO1 polymorphisms
- Inflammatory markers [ Time Frame: Baseline and end of study ]C-reactive protein, alpha glycoprotein
- Malaria [ Time Frame: Baseline and end of study ]A-symptomatic malaria

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Ages Eligible for Study: | 36 Months to 59 Months (Child) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Aged 36 - 59 months (verified by birth certificates, vaccination cards or other formal documentation)
- Apparently healthy
- Parental informed consent
Exclusion Criteria:
- Frequently absent (>20% of feeding days) during run-in
- Children not assenting during blood collections
- Signs or history of infectious or systemic diseases (e.g. tuberculosis, sickle cell anaemia)
- Mental status that is incompatible with the proper conduct of the study
- Current participation in other research
- Food allergy related to the intervention foods

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02627222
Nigeria | |
Department of Human Nutrition, University of Ibadan | |
Ibadan, Nigeria |
Principal Investigator: | Alida Melse-Boonstra, PhD | Division of Human Nutrition, Wageningen University |
Responsible Party: | Wageningen University |
ClinicalTrials.gov Identifier: | NCT02627222 |
Other Study ID Numbers: |
CASSAVITA II |
First Posted: | December 10, 2015 Key Record Dates |
Last Update Posted: | February 5, 2020 |
Last Verified: | January 2020 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Undecided |
Pro-vitamin A Cassava Vitamin A deficiency |
Retinol Isotope Dilution Preschool children Nigeria |
Night Blindness Vitamin A Deficiency Avitaminosis Deficiency Diseases Malnutrition Nutrition Disorders Vision Disorders Eye Diseases |
Vitamin A Provitamins Vitamins Micronutrients Nutrients Growth Substances Physiological Effects of Drugs |