Nycalopia or Night Blindness is a side effect of Vitamin A deficeincy. Vitamin A is a fat soluble vitamin that occurs in animal tissue as retinol. There are a number of different provitamins in food of vegetable origin. Beta carotene and other carotenoids, yellow and red carotenoid pigments, can be changed to vitamin A in the liver.
A number of functions for vitamin A have been found, including immune mechanisms, maintenance of healthy epithelial tissues, facilitates the mobilization iron from stores to developing red blood cells, and most importantly, a function in the visual system. Vitamin A deficiency may manifest itself by: 1.) A scale-like appearance in the skin and occasional acne, 2.) A failure of growth in young animals, including C. station of skeletal growth, and 3.) A failure of reproduction associated with atrophy of the epithelial cells of the testes and interruption of the female sexual cycle. Zinc works with Vitamin A by converting retinol to retinal and also protects from toxicity of Vitamin A. Vitamin A deficiency can worsen Iron Deficiency Anemia. It has been shown that treatment for Iron Deficiency Anemia responds better when Vitamin A and Iron are supplemented together.
Vitamin A deficiency may also represent a decreased visual acuity, more specifically, night blindness. Night Blindness was found in a patient who reported that they were unable to read a particular sign at night while driving, but was able to read it during the day. The body uses Vitamin A to make retinal, part of a molecule called rhodopsin. Rhodopsin is found in the rods of the eye. The rods are the cells of the retina that allow you to see in low light conditions. Here is a video of a patient exhibiting the effect of night blindness.
If Vitamin A deficiency is left untreated at the stage of night blindness it can progress to Xerophthalmia. Xerophthalmia is also caused by Vitamin A deficiency. The symptoms of Xerophthalmia is lack of tear production which are the lubrication of the eye. This leads to corneal and conjunctiva inflammation and thickening. The cornea can become cloudy and foamy spots (Bitot’s spots) leading to scarring and damage that effect the sight.
When a patient is diagnosed with vitamin A deficiency, the treatment will require aggressive oral supplementation. Duodenal Switch patients will only respond to “Dry” water miscible form of Vitamin A, which is pictured below/right. This “Dry” water miscible form is a powder which is designed to dissolve in water without the addition of bile for absorption. When taking oral vitamin A, it is important for patients who have had the Duodenal Switch operation to specifically look for a “Dry” water miscible form of vitamin A. This is to maximize the amount of vitamin A that can be absorbed even in the presence of reduced fat absorption.
For cases in which vitamin A levels do not respond to “Dry” water miscible Vitamin A oral supplementation, intramuscular injections may be required. The usual injected dosage of vitamin A is between 25,000-50,000 international units. Repeated injections in a 3-month interval have been required in some patients to normalize the vitamin A level, as well as resolving the symptom of night blindness.
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