Vitamin A deficiency among Brazilian school-aged children in a healthy child service - Custodio, V. I. C.; Daneluzzi, Júlio Cesar; Custodio, R. J.; Del Ciampo, Luiz Antonio; Ferraz, I. S.; Martinelli Júnior, Carlos Eduardo; Ricco, Rubens Garcia; Cupo, Palmira; Hering, Sylvia Evelyn; Meirelles, M. S. S.; Vannucchi, Hélio (European Journal of Clinical Nutrition, 2009)