Waardenburg syndrome (WS) is named after the Dutch ophthalmologist Petrus Johannes Waardenburg, who, in 1947, first described a patient with hearing loss, dystopia canthorum (ie, lateral displacement of the inner canthi of the eyes), and retinal pigmentary differences.
Vitamin A Deficiency-Related Disorders (VADD). The most damaging micronutrient deficiencies in the world are the consequence of low dietary intake of iron, vitamin A, iodine and zinc.Vitamin A deficiency (VAD) is prevalent among the poor whose diets are based mainly on rice or other carbohydrate-rich, micronutrient-poor calory sources.itamin A Deficiency-Related Disorders (VADD). The most damaging micronutrient deficiencies in the world are the consequence of low dietary intake of iron, vitamin A, iodine and zinc.
Vitamin A is a fat-soluble vitamin that is naturally present in many foods. Vitamin A is important for normal vision, the immune system, and reproduction. Vitamin A also helps the heart, lungs, kidneys, and other organs work properly.There are two different types of vitamin A. The first type, preformed vitamin A, is found in meat, poultry, fish, and dairy products.The second type, provitamin A, is found in fruits, vegetables, and other plant-based products. The most common type of provitamin A in foods and dietary supplements is beta-carotene.itamin A is important for normal vision, the immune system, and reproduction. Vitamin A also helps the heart, lungs, kidneys, and other organs work properly. There are two different types of vitamin A. The first type, preformed vitamin A, is found in meat, poultry, fish, and dairy products.