Vitamin A deficiency is a major public health problem in the developing world affecting 190 million children under 5 years old, particularly in sub-Saharan Africa and southeast Asia (WHO, 2009).
Vitamin A deficiency leads to impaired vision, diminishes the ability to fight infections and decreases growth rate and bone development, and in severe cases can be fatal for children under 6 years of age (WHO, 2004).
The prevalence of vitamin A deficiency in the Democratic Republic of Congo (DRC) and Burundi was estimated at 42.2% and 42.6%, respectively, in 2007, and is classified as a ‘‘severe public health problem’’ by the United Nations’ Standing Committee on Nutrition (SCN, 2010).
Vitamin A deficiency primarily affects children and women and hinders the development of human potential, with effects on social and economic development (Ruel, 2001).