User:Mr. Ibrahem/Vitamin A deficiency

Vitamin A deficiency (VAD) is a lack of vitamin A. Night blindness is one of the first symptoms. More severe disease may result in dry eyes, corneal ulcers, and blindness. It may also results in an increased risk of severe infections, such as with measles, and follicular hyperkeratosis.

It occurs due to a lack of vitamin A in the diet; which is generally from animal products, fruits or vegetables. Risk factors may include a high rate of infections, including diarrhea, inflammatory bowel disease, and following bariatric surgery. There are two dietary forms of vitamin A: retinols and carotenoids. Diagnosis is based on a blood retinol levels of less than 0.7 μmol/L (20 μg/dL), with less than 0.35 μmol/L (10 μg/dL) indicating severe disease.

Initial treatment is with 200,000 international units (IU) of vitamin A given once a day for two days. Further doses may be given every two weeks. In 2020, about 40% of at risk children aged 6 month to 5 years received two doses of vitamin A, which decreased their risk of death by 12 to 24%.

VAD is common in developing countries, particularly those in Africa and South-East Asia; however, it is rare in developed countries. About 190 million children under five and 19 million pregnant women are estimated to be affected. About 250,000–500,000 children in developing countries become blind each year as a result, making it the leading cause of preventable childhood blindness. Among those who become blind, about half die within a year. It is particularly common in the later part of pregnancy, and results in poor outcomes both for the mother and baby.