Vitamin A Deficiency

Key Features

• 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

• 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

• Abnormalities of dark adaptation

• Serum vitamin A levels below normal range of 30–65 mg/dL

Treatment

• 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