Traditional breeding techniques have been used for centuries to improve the color and organoleptic qualities of carrots.  Biofortification of staple crops with provitamin A carotenoids has emerged rather recently and is a potential long-term, sustainable approach to improve vitamin A status in groups at risk of vitamin A deficiency.  Unlike current fortification and supplementation efforts which largely use preformed vitamin A, biofortification through enhancing provitamin A carotenoids offers a natural approach to improving vitamin A status without the risk of hypervitaminosis A.  Globally, less emphasis has been placed on dietary diversification because of the difficulties in persuading people to change their diets.  While biofortication could be considered a form of dietary diversification, it differs in that it nutritionally improves the main energy sources of the diet without the addition of complementary foods.  Nutritionists do not dispute the benefits of a diversified diet, but it is often difficult to achieve this idealized diet in resource-poor areas of the world.  Crops that have been targeted for biofortification with provitamin A carotenoids include maize, cassava, sweet potato, and rice.  After successfully showing that biofortified maize can maintain the vitamin A status of Mongolian gerbils, we have simulated how biofortified maize will improve the vitamin A status of children from infancy through adolescence.  Unlike periodic supplementation that results in oscillation of liver vitamin A reserves or the potential for hypervitaminosis A with food fortification, biofortified maize results in a steady increase in liver concentrations and a plateau once liver reserves are high.  Biofortification of staple crops with provitamin A carotenoids should continue and efforts need to focus on familiarizing consumers with the nutritional benefits of deeper colored foods to build awareness and demand.