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Vitamin A | Independent Newspapers Nigeria

Daily Independent logo Daily Independent 2020-06-20 By Our Correspondents

Foods rich in vitamin A do much more than help prevent your eyesight from declining and help you see in the dark. They are also good effective antioxidants that helps keep free radicals at bay.

Vitamin A can help one look refreshingly young, repair a lot of damages done to the tissues by protecting the skin from wrinkles, keep hair from turning white, prevents joints from stiffening and muscles from weakening.

Vitamin A plays a key role in the immune system function. It helps prevent colds and flus; protects against infections in the vital organs of the body and regulates cell growth and division.

Vitamin A also takes part in remodeling bones and teeth, weak digestion, sexual weakness and prevents some forms of cancer and other problems related to aging.

Various researches have shown the relationship between vitamin A and cancer especially those of the mouth, throat, stomach, prostrate and kidneys. These anticarcinogenic properties can be attributed partly to its antioxidant properties, but also to various other medicinal properties of its natural components.

One can also reduce their cancer risk by taking supplements of beta-carotene, one of several precursor compounds that the body can transform into vitamin A, or by taking the active form of vitamin A (also called retinol).

The question now is what quantity of vitamin A should one consume? The United State Institute of Medicine, recommends intake of vitamin A to be 900 micrograms of retinol for men (equivalent to 3,000 IU) and 700 micrograms of retinol for women (equivalent to 2,333 IU). The upper limit for vitamin A intake from retinol is 3,000 micrograms, but intakes that are high may increase the risk of hip fracture or interfere with the beneficial actions of vitamin D. For children 1000 to 2000 IU is recommended.

Excessive intake of vitamin A should be avoided during pregnancy because this may lead to some confusion and birth defects. Pregnant women should avoid use of vitamin A supplements and also avoid eating liver and liver products because liver is a particularly concentrated source of vitamin A. But women who are at risk of becoming pregnant should keep their supplemental vitamin A levels below 5000IU or choose carotenoids such as beta-carotene.

Be careful not to take vitamin A in excess because excessive amounts may be toxic and could lead to liver damage, jaundice, nausea, loss of appetite, irritability, vomiting, and even hair loss.

Mild deficiency of vitamin A may result in: retarded growth, increased susceptibility to infection, abnormal function of gastro intestinal, genitourinary, and respiratory tracts due to altered epithelial membranes, dry, shriveled, thickened skin. Severe deficiency may result in: xerophthalmia, a characteristic eye disease, and other local infections.

Doses greater than 10,000IU a day of vitamin A were reported in the New England Journal of Medicine to have probably been responsible for one out of fifty-seven birth defects in the United States.

Smokers should avoid high-dose single supplements of beta-carotene, since some randomized trials in smokers have linked high dose supplementation with increased lung cancer risk.

Carrots are an excellent source of vitamin A (in the form of carotenoids). Carrots are perhaps best known for their beta-carotene content. (The nutrient beta-carotene was actually named after the carrot).

Other food sources of vitamin A rich in retinol are: milk fats, butter, cheese, cream, whole milk, egg yolk, liver, fatty fish. Sources of vitamin A rich in carotene are: green leafy vegetables, carrots, fruits (yellow and red coloured fruits are also very rich vitamin A sources).

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