Effect of Provitamin A-biofortified Cassava on Vitamin A Status of Kenyan Children: A Randomised Controlled Trial
Elise F. Talsma *
Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.
Inge D. Brouwer
Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.
Hans Verhoef
Cell Biology and Immunology Group, Wageningen University, Wageningen, The Netherlands and London School of Hygiene and Tropical Medicine, MRC International Nutrition Group, London, UK,
Alice M. Mwangi
Applied Nutrition Programme, Department of Food Technology and Nutrition, University of Nairobi, Nairobi, Kenya.
Erick Boy
Harvest Plus, Washington, USA.
Busie B. Maziya-Dixon
International Institute of Tropical Agriculture, Ibadan, Nigeria,
Michael B. Zimmermann
Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands and Human Nutrition Laboratory, Institute of Food, Nutrition and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.
Alida Melse-Boonstra
Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.
*Author to whom correspondence should be addressed.
Abstract
Objectives: To measure the effect of daily consumption of provitamin A-biofortified cassava on vitamin A status in children aged 5-13 years.
Methods: Mild-to-moderate vitamin A deficient children (n=342) were randomly allocated to groups receiving: 1) 375 g of white cassava and placebo supplement; 2) 375 g of white cassava and a supplement of β-carotene (1,054 µg); 3) 375 g of biofortified cassava and placebo supplement. Children received the intervention 6 days/week for 18.5 weeks. Field staff and participants were blinded to supplementation. Cooked cassava was mashed with salt and 4 g of oil per portion. Biofortified cassava supplied 208 µg RAE, which is ~50% of the age-specific estimated average requirement for vitamin A for children. The primary endpoint was serum retinol concentration and secondary endpoint was serum β-carotene concentration, both at end of intervention; in the analysis, we adjusted for sex and serum concentrations at baseline of retinol, C-reactive protein and α1-acid-glycoprotein.
Results: Complete data were collected for 337 children. Compliance to cassava feeding was similar between treatment groups. Preliminary results showed that consumption of biofortified cassava and β-carotene supplementation resulted in a similar increase in retinol concentrations (for both interventions, mean: 0.81 μmol/L versus 0.77 μmol/L; difference, 95% CI: 0.04 μmol/L, 0.00─0.07 μmol/L) but in a different increase in serum β-carotene concentration (for β-carotene supplement group, mean: 0.25 μmol/L (95% CI: 0.17─0.33), for biofortified cassava group, mean: 0.81 μmol/L (95% CI: 0.73-0.88))
Conclusions: Provitamin A-biofortified cassava improves the vitamin A status of primary school children in Kenya.