Vitamin A Deficiency
Conditions
Keywords
Pro-vitamin A, Cassava, Vitamin A deficiency, Retinol Isotope Dilution, Preschool children, Nigeria
Brief summary
The study comprises an open-label randomized controlled trial investigating the efficacy of consuming a daily ration of pro-vitamin A biofortified cassava on vitamin A status of Nigerian children, aged 3-4 years old (n=200).
Detailed description
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.
Interventions
OTHERPro-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
OTHERWhite cassava
Conventional white cassava
Sponsors
University of Ibadan
International Institute for Tropical Agriculture
Wageningen University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
36 Months to 59 Months
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Body retinol pool (omitted) | 13 weeks | Difference in body retinol pools between groups |
| (Modified primary outcome): Serum retinol | 13 weeks | Difference in serum retinol pools between groups |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Anaemia | 13 weeks | Difference in haemoglobin concentration between groups |
| Gut integrity | 11 weeks | Difference in gut integrity between groups |
Other
| Measure | Time frame | Description |
|---|---|---|
| Serum zinc | Baseline | Effect modification by baseline zinc deficiency |
| Genetic polymorphisms in the BCO1 gene | Baseline | Effect modification by BCO1 polymorphisms |
| Serum betacarotene | 13 weeks | Difference in serum retinol concentration between groups |
| Malaria | Baseline and end of study | A-symptomatic malaria |
| Inflammatory markers | Baseline and end of study | C-reactive protein, alpha glycoprotein |
| Retinol binding protein | 13 weeks | Difference in serum retinol binding protein concentration between groups |
| Urinary thiocyanate | 11 weeks | Difference in urinary thiocyanate concentration between groups |
| Thyroid function indicators | 13 weeks | Difference in serum thyroid function indicators between groups |
Countries
Nigeria
Outcome results
None listed