1. Fawzi WW, Chalmers TC, Herrera MG, F Mosteller M. Vitamin A supplementation and child mortality. A metaanalysis. JAMA.1993; 17;269:898–903.
2. Imdad A, Herzer K, Mayo-Wilson E, Yakoob MY, Bhutta ZA. Vitamin A supplementation for preventing morbidity and mortality in children from 6 months to 5 years of age. Cochrane Database Syst Rev. 2010;12:CD008524.
3. World Health Organization. World Health Organization Nutrition for Health and Development Guideline. 2011. Accessed February 11,2022. Accessed on February 13, 2022. Available from: http://whqlibdoc.who.int/publications/2011/9789241501767_eng.pdf
4. Awasthi S, Peto R, Read S, et al. Vitamin A supplementation every 6 months with retinol in 1 million pre-school children in north India: DEVTA, a cluster-randomised trial. Lancet. 2013;381:1469–77.
5. Imdad A, Mayo-Wilson E, Herzer K, Bhutta ZA. Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age. Cochrane Database Syst Rev. 2017;3:CD008524.