​Pathology - Vitamin A Deficiency

​Pathology - Vitamin A Deficiency 
Pathophysiology 
 Vitamin A is necessary for both the upkeep of the surface of the eyes and eyesight, particularly in the dark.
Additionally, normal immunological response as well as the growth and repair of epithelial cells depend on it. While it is rare in affluent nations, vitamin A insufficiency is widespread in poor nations. The majority of vitamin A is stored in the liver and released into the bloodstream with the use of a carrier protein. Vitamin A is a fat-soluble vitamin that is absorbed in the small intestine through the chylomicron pathway. Fat malabsorption-related disorders will reduce the absorption of vitamin A in the intestines, whereas liver disorders will reduce the storage of vitamin A.
The cycling of visual pigment molecules in the retina is insufficient to support vision in low light when retinal concentration is too low. The patient exhibits symptoms of poor surface upkeep, such as "Bittot's spots" and dry eyes. In children in the underdeveloped world, corneal scarring is a major cause of blindness and can happen. Recurrent colds and coughing are indicative of lowered immunity. Oral vitamin pills are a simple way to address the disease.