An example of MS-DOS's command-line interface, this one showing that the current directory is the root of drive C. MS-DOS (/ËÉmÉsËdÉs/ EM-es-DOSS; acronym for Microsoft Disk Operating System) is a discontinued operating system for x86-based personal computers mostly developed by Microsoft.
Written by: Kierstan Boyd. Nov. 08, 2012. The main symptom of vitamin A deficiency is vision loss and blindness. Vision loss often begins as a problem adjusting to seeing in the dark, or night blindness. People with night blindness do not see well in the dark, but are able to see normally if enough light is present.
1 A diet which is rich in Vitamin A is usually the treatment and the best prevention method of vitamin A deficiency. 2  Liver, kidney, milk, cheese, cream and butter are rich sources of Vitamin A. Vitamin A can also be absorbed in the body through Carotene which is found in vegetables which have dark green vegetables. Mal-absorption of vitamin A by the body can also lead to its deficiency. 2  It can be due to sprue, celiac disease, obstructive jaundice, cirrhosis, giardiasis, cystic fibrosis or an over use of mineral oil as laxative. 3  Over excretion of urine is also known to cause Vitamin A deficiency.