California is a major producer of tangerines and oranges, which contain carotenoids that form vitamin A. Deficiencies of this vitamin are common in southern Asia and Africa, causing blindness and more than one-half million deaths each year. We evaluated the potential of tangerines and oranges to prevent vitamin A deficiency worldwide by measuring their carotenoid concentrations, estimating the amounts needed to meet the recommended safe nutrient intake for vitamin A and determining their availability in countries with vitamin A deficiency. We conclude that tangerines — particularly Satsuma mandarins, which have high concentrations of the carotenoid beta-cryptoxanthin — but not oranges, could be useful in preventing vitamin A deficiency, though not as the sole source.