title: The continuing challenge of vitamin A deficiency.
authors.forename: Alfred
authors.initials: A
authors.lastname: Sommer
mesh_terms: D006801:Humans; D007194:India / Q000453:epidemiology; D010154:Pakistan / Q000453:epidemiology; D014802:Vitamin A Deficiency / Q000453:epidemiology* / Q000517:prevention & control; D014985:Xerophthalmia / Q000453:epidemiology* / Q000517:prevention & control