Mr. Ibrahem/Vitamin A deficiency | |||
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Other names | Hypovitaminosis A | ||
State of vitamin A deficiency, 1995
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Specialty | Pediatrics, ophthalmology | ||
Symptoms | Night blindness, dry eyes, corneal ulcers[1][2] | ||
Complications | Blindness[2] | ||
Causes | Lack of vitamin A in the diet[2] | ||
Risk factors | High rate of infections, inflammatory bowel disease, bariatric surgery[1][3] | ||
Diagnostic method | Blood retinol < 0.7 μmol/L (20 μg/dL)[1] | ||
Differential diagnosis | Retinitis pigmentosa, cataracts, near-sightedness[3] | ||
Treatment | Vitamin A supplementation[3] | ||
Frequency | Developing countries: Common[1] Developed countries: Rare[1] |
Vitamin A deficiency (VAD) is a lack of vitamin A.[2] Night blindness is one of the first symptoms.[1] More severe disease may result in dry eyes, corneal ulcers, and blindness.[2] It may also results in an increased risk of severe infections, such as with measles, and follicular hyperkeratosis.[2]
It occurs due to a lack of vitamin A in the diet; which is generally from animal products, fruits or vegetables.[2] Risk factors may include a high rate of infections, including diarrhea, inflammatory bowel disease, and following bariatric surgery.[1][3] There are two dietary forms of vitamin A: retinols and carotenoids.[2] 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.[1]
Initial treatment is with 200,000 international units (IU) of vitamin A given once a day for two days.[2] Further doses may be given every two weeks.[3] 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%.[4]
VAD is common in developing countries, particularly those in Africa and South-East Asia; however, it is rare in developed countries.[1] About 190 million children under five and 19 million pregnant women are estimated to be affected.[2] 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.[2][1] Among those who become blind, about half die within a year.[2] It is particularly common in the later part of pregnancy, and results in poor outcomes both for the mother and baby.[2][1]
References edit
- ^ a b c d e f g h i j k "Vitamin A deficiency". www.who.int. Archived from the original on 1 November 2021. Retrieved 8 February 2022.
- ^ a b c d e f g h i j k l m "Vitamin A". Micronutrient Information Center, Linus Pauling Institute, Oregon State University, Corvallis. January 2015. Archived from the original on 27 April 2021. Retrieved 1 November 2019.
- ^ a b c d e Hodge, Christopher; Taylor, Christopher (2022). "Vitamin A Deficiency". StatPearls. StatPearls Publishing. Archived from the original on 15 October 2021. Retrieved 8 February 2022.
- ^ "Vitamin A Deficiency and Supplementation UNICEF Data". Archived from the original on 2016-09-11. Retrieved 2015-04-07.