維生素A
Global efforts to support national governments in addressing VAD are led by the Global Alliance for Vitamin A (GAVA), which is an informal partnership between Nutrition International, Helen Keller International, UNICEF, WHO, and CDC. About 75% of the vitamin A required for supplementation of preschool-aged children in low- and middle-income countries is supplied through a partnership between Nutrition International and UNICEF, with support from Global Affairs Canada. An estimated 1.25 million deaths due to vitamin A deficiency have been averted in 40 countries since 1998. In 2013, the prevalence of vitamin A deficiency was 29% in low-income and middle-income countries, remaining highest in sub-Saharan Africa and South Asia. A 2017 review found that vitamin A supplementation in children 5 years old and younger in 70 countries was associated with a 12% reduction in mortality rate. The review reported that synthetic vitamin A supplementation may not be the best long‐term solution for vitamin A deficiency, but rather food fortification, improved food distribution programs, and crop improvement, such as for fortified rice or vitamin A-rich sweet potato, may be more effective in eradicating vitamin A deficiency.