Effect of Vitamin A, Zinc and Multivitamin Supplementation on the Nutritional Status and Retinol Serum Values in School-Age Children. - Carmen Carrero; Jorymar Leal; Pablo Ortega; Alexander Parody; Marilyn Montilla; Leandro Sierra; Amelec Viloria; Tito Crissien Borrero; Noel Varela (DMBD, 2018)