Prevention of blindness due to hypovitaminosis A.
D000367:Age Factors; D001766:Blindness / Q000517:prevention & control*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D011502:Protein-Energy Malnutrition / Q000150:complications; D012959:Socioeconomic Factors; D014801:Vitamin A / Q000627:therapeutic use; D014802:Vitamin A Deficiency / Q000150:complications* / Q000517:prevention & control; D014985:Xerophthalmia / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*
D014801:Vitamin A