Healthy Lifestyle Tips

Every day health guidelines to stay strong and healthy

  • Historically,  vitamin A has been most well known as a cure for night blindness. In fact, night blindness is a symptom of vitamin A deficiency, which can be alleviated by taking sufficient amounts of that vitamin. Symptoms of night blindness were first recognized in ancient Egypt around 1500 B.C. Although at the time the problem was not linked to a dietary deficiency of any kind, the symptoms were treated by placing roasted or fried liver over the eyes. Later, Hippocrates suggested eating beef liver, a rich source of vitamin A, as a cure for night blindness. Today we known that vitamin A serves several other important functions in the body, and chemical derivatives of vitamin A have important medical benefits, particularly in the area of treatment of skin conditions and in cancer treatment. We also know that vitamin A deficiencies lead to a higher risk for some cancers. Including lung cancer in smokers.

    Several compounds with similar chemical structures in nature have vitamin A activity. In animal - derived foods, most vitamin A exists as retinol or retinal. Vitamin A from plants is in the form of carotenoids. Carotenoids are considered "provitamins"  because they must be metabolized in the body before they can act as a vitamin. Alone, however, they may serve as free-radical scavengers and quenchers of singlet oxygen. There are many carotenoids in plants, but not all have vitamin A activity. Beta carotene is the most common, and it has the most potent vitamin A activity. 

    All compounds with vitamin A activity are fat-soluble; like all fats, they are absorbed from the intestinal  tract with the help of bile.

    FUNCTIONS

    Vitamin A in essential to a variety of biochemical and physiological processes, the vitamin must undergo a minor chemical change to allow it to participate in that function. Vitamin A, as retinal, is a part of the pigment called rhodopsin, found in the retina of the eye. Rhodospin in sensitive to small amounts of light and is essential for night vision because it allows us to discern object in very low light. To function in this way, the retina of the eye must contain a large concentration of vitamin A.


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