A proven solution to VAD is at our fingertips. Vitamin A supplementation is simple, cost-effective, and together with zinc supplementation was ranked by a group of world-renowned economists as the top international priority for addressing the world's greatest global development challenges. Unlike other treatments, one high-dose vitamin A capsule can provide one child with sufficient vitamin A for six months. This alone can reduce under-five child mortality by about 24% in populations at risk of vitamin A deficiency. It can also help prevent and reverse one of the most severe effects of VAD, xerophthalmia, a disorder of the eye that can lead to permanent blindness.