By Nita McKinney
Vision vitamins are an important component of our everyday diet. Apart from the vitamin A which is widely known for its important properties, there are many others that play a central role in maintaining good eyesight. These nutritional elements include vitamin B6 and C and others such as selenium, zinc and magnesium among others. There are many different types of foods that contain many of these elements in different combinations. Examples include green leafy vegetables, oranges, carrots and pumpkins among others.
Vitamin A is important for continuous eye health. It facilitates better vision by influencing the synthesis of the pigmented rhodopsin found in the retina. It promotes good night vision or helps one see better in dim light. In addition, it ensures the cornea is kept moist by maintaining the integrity of related membranes.
It should be understood that vitamin A is not a single unit. Rather, it is made of several non-saturated hydrocarbons. These hydrocarbons include retinoic acid, retinol, retinal and other precursors known as carotenoids. Beta carotene is the most important of these carotenes. The retinal hydrocarbon reacts with a protein known as opsin to form rhodopsin. The resultant molecule helps in the achievement of scotopic (low light) and colour vision.
A deficiency in vitamin A may lead to various eye problems ranging from mild, moderate to severe manifestation depending on the chronicity of the deficiency. Lack of this crucial vitamin can either be primary or secondary. A primary deficiency is due inadequate intake of either provitamin A carotenoids (vegetables and fruits) or the preformed vitamin from dairy and animal products. This is the commoner form.
The secondary form of deficiency is as a result of malabsorption of lipids and deficient bile production and release. This is explained by the fact that the A vitamin is a fat soluble vitamin and therefore requires dissolution in fat in fat for it become functional in the body. As such, a low fat diet can predispose one to disease states related to deficiency of respective vitamins. Long term exposure to oxidants including cigarette smoke and alcohol intake can also lead to secondary insufficiency of vitamin A.
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.
Vitamins C and B6 play a minor role but are still very important. Vitamin C is an antioxidant that protects the eye against the effects of irradiation. It also maintains capillary and collagen integrity and normal pressure. B6 vitamin ensures that the red cell structure is intact and this in turn contributes to proper functioning of the retina. The mineral zinc is involved in the conversion of beta carotene to active vitamin A.
While it may not be possible to have all these vision vitamins in the diet at all times, it is wise to have them as many times as possible. The factors that determine intake include, among others, pregnancy, lactation, sex and age. It is important to take just enough in each serving to avoid toxicity.
Vitamin A is important for continuous eye health. It facilitates better vision by influencing the synthesis of the pigmented rhodopsin found in the retina. It promotes good night vision or helps one see better in dim light. In addition, it ensures the cornea is kept moist by maintaining the integrity of related membranes.
It should be understood that vitamin A is not a single unit. Rather, it is made of several non-saturated hydrocarbons. These hydrocarbons include retinoic acid, retinol, retinal and other precursors known as carotenoids. Beta carotene is the most important of these carotenes. The retinal hydrocarbon reacts with a protein known as opsin to form rhodopsin. The resultant molecule helps in the achievement of scotopic (low light) and colour vision.
A deficiency in vitamin A may lead to various eye problems ranging from mild, moderate to severe manifestation depending on the chronicity of the deficiency. Lack of this crucial vitamin can either be primary or secondary. A primary deficiency is due inadequate intake of either provitamin A carotenoids (vegetables and fruits) or the preformed vitamin from dairy and animal products. This is the commoner form.
The secondary form of deficiency is as a result of malabsorption of lipids and deficient bile production and release. This is explained by the fact that the A vitamin is a fat soluble vitamin and therefore requires dissolution in fat in fat for it become functional in the body. As such, a low fat diet can predispose one to disease states related to deficiency of respective vitamins. Long term exposure to oxidants including cigarette smoke and alcohol intake can also lead to secondary insufficiency of vitamin A.
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.
Vitamins C and B6 play a minor role but are still very important. Vitamin C is an antioxidant that protects the eye against the effects of irradiation. It also maintains capillary and collagen integrity and normal pressure. B6 vitamin ensures that the red cell structure is intact and this in turn contributes to proper functioning of the retina. The mineral zinc is involved in the conversion of beta carotene to active vitamin A.
While it may not be possible to have all these vision vitamins in the diet at all times, it is wise to have them as many times as possible. The factors that determine intake include, among others, pregnancy, lactation, sex and age. It is important to take just enough in each serving to avoid toxicity.
You can visit the website visionaryvites.com for more helpful information about Important Facts About Vision Vitamins
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