Detection of vitamin A deficiency in Brazilian preschool children using the serum 30-day dose-response test - Ferraz, Ivan Savioli; Daneluzzi, Julio Cesar; Vannucchi, Hélio; Jordão Junior, Alceu Afonso; Ricco, Rubens Garcia; Del Ciampo, Luiz Antonio; Martinelli Júnior, Carlos Eduardo; Engelberg, Alexander Antony D'Angio; Bonilha, Luís Roberto de Castro Martins; Flores, H. (European Journal of Clinical Nutrition, 2004)