Konya (Turkish pronunciation: [Ëkon.ja]; Greek: á¼°ÎºÏÎ½Î¹Î¿Î½ IkÃ³nion, Latin: Iconium) is a major city in the Central Anatolia Region of Turkey. It is the seventh-most-populous city in Turkey. As of 2016[update], Konya has a population of over 2.1 million.
Vitamin A is needed by the retina of the eye in the form of retinal, which combines with protein opsin to form rhodopsin, the light-absorbing molecule necessary for both low-light (scotopic vision) and color vision. Retinol, the form of vitamin A absorbed when eating animal food sources, is a yellow, fat-soluble substance. 2  Since the pure alcohol form is unstable, the vitamin is found in tissues in a form of retinyl ester. 3  It is also commercially produced and administered as esters such as retinyl acetate or palmitate.
Several of your tissues need vitamin A to function, so failure to get enough vitamin A causes a number of symptoms. You might notice that youâre less able to see well at night, because vitamin A supports vision in low light conditions.