Efficacy of Yellow Cassava to Improve Vitamin A Status of Kenyan School Children (CASSAVITA)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01614483
Recruitment Status : Completed
First Posted : June 8, 2012
Last Update Posted : January 30, 2013
European Commission
University of Nairobi
Information provided by (Responsible Party):
Alida Melse, Wageningen University

Brief Summary:
The overall aim of the project is to provide proof-of-principle that biofortification of cassava with vitamin A is a viable strategy to improve vitamin A status of deficient populations.

Condition or disease Intervention/treatment Phase
Vitamin A Deficiency Other: Yellow cassava Other: White cassava Not Applicable

Detailed Description:

Rationale: Vitamin A deficiency is still common in developing countries and has been proven difficult to combat. A promising approach is to replace common crops with varieties that are naturally richer in vitamin A, which is referred to as biofortification. For cassava, yellow β-carotene rich varieties have recently been introduced in Kenya, and these varieties are now ready to be tested for their efficacy to improve vitamin A status in humans.

Objective: The primary objective is to measure the effect of daily consumption of provitamin A biofortified cassava (providing 50% of the age-specific RDA) on vitamin A status in children aged 5-13 years with mild to moderate vitamin A deficiency in Kenya. To determine the bioefficacy of provitamin A carotenoids from biofortified cassava relative to that of a daily B-carotene supplement (comparison with positive control group). Secondary objectives are: 1) to measure the effect of the intervention on immune function indicators and morbidity; 2) to determine to what degree the serum retinol response to the intervention depends on serum concentrations of retinol and zinc at baseline; 3) to determine the effect of the intervention on functional indicators such as dark adaptation capacity, gut integrity, hematology indicators and thyroid status; 4) to determine the mediating effect of SNP's in the BCMO1 gene on treatment outcome.

Study design & Study population : In this randomized controlled trial, school children aged 5-13 years living in the Kibwezi area, Kenya. Children will be selected from three (or four) primary schools in the area that have been pre-selected based on the prevalence of vitamin A deficiency, location and willingness to participate.

Intervention: After screening for eligibility and a 2-week run-in period (n=360) Children will be randomly allocated to three different treatments: 1) 400 g of yellow cassava providing ~50% of the RDA for vitamin A; and a placebo capsule; 2) 400 g of white cassava; and a placebo capsule; 3) 400 g of white cassava and a capsule containing 100 RAE of all-trans β-carotene.

Main study parameters/endpoints: The main outcome measure will be differences in serum retinol concentrations between groups. Other outcome measures include other vitamin A status indicators (β-carotene, retinol binding protein, transthyretin), immune function indicators, dark adaptation, iron status indicators, anthropometrics, gut integrity, and thyroid function.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 341 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Efficacy of Yellow Cassava to Improve Vitamin A Status of Mildly Deficient Primary School Children in Kenya: a Randomized Controlled Trial
Study Start Date : May 2012
Actual Primary Completion Date : November 2012
Actual Study Completion Date : November 2012

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Vitamin A
Drug Information available for: Vitamin A

Arm Intervention/treatment
Experimental: Yellow cassava + placebo capsule Other: Yellow cassava
Daily provision of 375 g boiled yellow cassava for 18 weeks, 6 days/week Daily provision of placebo capsule for 18 weeks, 6 days/week

Placebo Comparator: White cassava + placebo capsule Other: White cassava
Daily provision of 375 g boiled white cassava for 18 weeks, 6 days/ week Daily provision of placebo capsule for 18 weeks, 6 days/ week

Active Comparator: White cassava + B-carotene capsule Other: White cassava
Daily provision of 375 g boiled white cassava for 18 weeks, 6 days/week Daily provision of B-carotene capsule (1400 µg B-carotene)

Primary Outcome Measures :
  1. Change in serum retinol concentration [ Time Frame: Baseline, end of study (4 months) ]

Secondary Outcome Measures :
  1. Immune function indicators [ Time Frame: End of study (4 months) ]
    neopterin, IL-2, IL4, IL10, IL13, TNF-a, IFN-γ, TGF-β in serum; IgA in saliva

  2. Bioefficacy [ Time Frame: Baseline, end of study (4 months) ]
    Comparison of change in serum retinol between yellow cassava group and positive control (B-carotene supplement group)

  3. Functional indicators [ Time Frame: End of study (4 months) ]
    Gut integrity, dark adaptation, morbidity

  4. Thyroid function [ Time Frame: End of study (4 months ]
    Serum Tg, TSH

  5. Effect modification [ Time Frame: Baseline ]
    Serum zinc, serum retinol, iron status, polymorphisms

  6. Anemia [ Time Frame: End of study (4 months) ]

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Ages Eligible for Study:   61 Months to 13 Years   (Child)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Low vitamin A status (retinol binding protein (RBP) at the lowest end of the distribution will be included in the study)

Exclusion Criteria:

  • History or signs of infectious or systemic diseases (e.g. tuberculosis, sickle cell anaemia)
  • Anaemia, malaria or acute inflammation at the day of baseline measurements

Information from the National Library of Medicine

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 identifier (NCT number): NCT01614483

Kibwezi District
Kibwezi, Eastern Kenya, Kenya
Sponsors and Collaborators
Wageningen University
European Commission
University of Nairobi
Principal Investigator: Alida Melse, PhD Wageningen University

Additional Information:
Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Alida Melse, PhD, Wageningen University Identifier: NCT01614483     History of Changes
Other Study ID Numbers: INSTAPAWP2YC
First Posted: June 8, 2012    Key Record Dates
Last Update Posted: January 30, 2013
Last Verified: January 2013

Keywords provided by Alida Melse, Wageningen University:
Vitamin A deficiency
School children

Additional relevant MeSH terms:
Vitamin A Deficiency
Night Blindness
Deficiency Diseases
Nutrition Disorders
Vision Disorders
Eye Diseases
Vitamin A
Beta Carotene
Retinol palmitate
Growth Substances
Physiological Effects of Drugs
Molecular Mechanisms of Pharmacological Action
Protective Agents
Anticarcinogenic Agents
Antineoplastic Agents