what are vitamins

Important Facts About Vision Vitamins

 what are vitamins Vision vitamins are the nutritional elements that enhance eye sight. These include vitamin A, B6, C, selenium, trace elements such as magnesium and zinc among other nutrients. A variety of food containing vitamins include, among others oranges, carrots, pumpkin and leafy vegetables. Having enough of these food sources in the diet protects one from getting certain eye diseases such as cataracts and macular degeneration.    vitamin c sources  what are vitamins: 

We will explore the benefits of vitamin A in more detail since it is the nutrient of greatest significance. The vitamin is involved in the synthesis of a pigment of the retina known as rhodopsin. Rhodopsin is necessary for dim vision. The other important role that this pigment plays is that it helps to keep the cornea moist through the    maintenance of the integrity of related membranes.  vitamin c sources   what are vitamins

The A vitamin is not a single unit as such but is composed of a group of hydrocarbons which are not saturated. These include retinoic acid, retinal, retinol and a number of vitamin A precursors (carotenoids). The most important among the pro vitamin A carotenoids is beta carotene. Retinal component combines with the protein opsin to form rhodopsin. The so formed light absorbing molecule is vital for both colour and low light (scotopic) vision.  what are vitamins

Lack of vitamin A causes many eye problems whose severity varies depending on the period of time one is affected and the extent of deficiency. Such a deficiency will be caused by inadequate amounts of vitamin A in the diet for a long time. This is called primary vitamin A deficiency. Its prevention entails frequent intake of carotenoid containing foods such as fruits, vegetables and dairy products.   what are vitamins

Secondary deficiency may be seen in a number of circumstances. For instance, it is seen when there is malabsorption of the vitamin. This frequently occurs when there is decreased uptake of lipids and reduced release of bile. The vitamin requires fat to dissolve and a deficiency of the fats will therefore result in decreased absorption. Other risk factors for the same include prolonged smoking and alcohol intake.  vitamin c sources   what are vitamins

One of the most initial manifestations of vitamin A deficiency is night blindness. This refers to impaired scotopic vision. With time, the condition may worsen and changes such as drying of the conjunctiva may occur. This happens because the normal tear secreting system is replaced by keratinisation. This is accompanied by formation of keratin plaques in the cornea which eventually gets eroded as more keratinisation leading to complete blindness. vitamin c sources

The other vitamins play a relatively minor role. Vitamin C has antioxidant properties which help protect the eye from irradiation. It is also important in the maintenance of capillary integrity and normal pressure. The B6 vitamin maintains red cell structure and function and thus ensures that the retina functions optimally. Zinc takes part in the conversion of beta carotene to vitamin A.  vitamin c sources