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.
Your body has no way to create vitamin molecules itself, so the vitamin molecules must come in through food that you eat. The human body is known to need at least 13 different vitamins: Inside the body, vitamins are used in many unique ways. For example, one of vitamin A's main roles is in the production of retinal. Retinal is used within the rods and cones in your eyes to sense light. There is no way for your body to produce retinal without vitamin A, and without retinal you cannot see.