Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 29-18: Vitamin A Deficiency + Key Features Download Section PDF Listen +++ ++ One of the most common vitamin deficiency syndromes in developing countries Most common cause of blindness in developing countries In the United States, occurs most commonly in the elderly and individuals of lower socioeconomic status or from fat malabsorption syndromes or mineral oil laxative abuse + Clinical Findings Download Section PDF Listen +++ ++ Night blindness (early) Dryness (xerosis) of conjunctivae and small white patches on the conjunctivae (Bitot spots) (early) Ulceration and necrosis of the cornea (keratomalacia), perforation, endophthalmitis, and blindness (late) Xerosis and hyperkeratinization of the skin Loss of taste + Diagnosis Download Section PDF Listen +++ ++ Abnormalities of dark adaptation Serum vitamin A levels below normal range of 30–65 mg/dL + Treatment Download Section PDF Listen +++ ++ Early deficiency: vitamin A 30,000 international units orally once daily for 1 week Advanced deficiency: vitamin A 20,000 international units/kg orally once daily for at least 5 days