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Vitamin A - Benefits, Deficiency Symptoms And Food Sources

By: alien

Vitamin A, a fat-soluble vitamin, plays essential roles in vision, growth, and development; the development and maintenance of healthy skin, hair, and mucous membranes; immune functions; and reproduction.

Functions and benefits of Vitamin A

Vitamin A maintain healthy teeth, skeletal and soft tissue, mucous membranes, and skin. Vitamin A promotes good vision, especially in dim light. It may also be required for reproduction and breast-feeding.

Carotenoids are dark colored dyes found in plant foods that can turn into a form of vitamin A. One such carotenoid is beta-carotene. Beta-carotene is an antioxidant. Antioxidants protect cells from damage caused by unstable substances called free radicals. Free radicals are believed to contribute to certain chronic diseases and play a role in the degenerative processes seen in aging.

Benefits of vitamin A in human body are :-

* It helps us to see in dim light.
* It helps us to grow bones normally.
* Assists maintaining health skin and mucous membranes protecting the body's major organs.
* Vitamin A is considered a fat-soluble vitamin. This means it is stored in your body’s fat cells and liver until used.
* Vitamin A great tool for fighting infection.

Recommended Dosage for Vitamin A

The RDA for vitamin A is 4,000 IU every day for women and 5,000 IU every day for men. Higher doses are typically given for due to any illness of these vitamins.

Food sources of Vitamin A

Retinol is found in foods that come from animals such as whole eggs, milk, and liver.

Fortified foods such as fortified breakfast cereals also provide vitamin A. Provitamin A carotenoids are abundant in darkly colored fruits and vegetables. Major dietary contributors of retinol are milk, margarine, eggs, beef liver and fortified breakfast cereals, whereas major contributors of provitamin A carotenoids are carrots, cantaloupes, sweet potatoes, and spinach.

Deficiency Symptoms of Vitamin A

Associated with the high incidence of blindness, viral infections, and child mortality that occurs in impoverished populations. Vitamin A deficiency affects the health of the skin, hair, eyes, and immune system, though loss of appetite, bone abnormalities, and growth retardation are also associated with inadequate intake of this vitamin.

A tell-tale sign of vitamin A deficiency is hyperkeratosis, a goose bump-like appearance of the skin caused by excessive production of keratin that blocks hair follicles. In initial stages, hyperkeratosis is found on the forearms and thighs, where the skin becomes dry, scaly, and rough. In advances stages, hyperkeratosis affects the whole body, causing hair loss.

Described as low storage levels of vitamin A that do not cause obvious deficiency symptoms. This mild degree of vitamin A deficiency may increase children's risk of developing respiratory and diarrheal infections, decrease growth rate, slow bone development, and decrease likelihood of survival from serious illness. Children considered to be at increased risk for subclinical vitamin A deficiency include :-

* toddlers and preschool age children;
* children living at or below the poverty level;
* children with inadequate health care or immunizations;
* children living in areas with known nutritional deficiencies;
* recent immigrants or refugees from developing countries with high incidence of vitamin A deficiency or measles; and
* children with diseases of the pancreas, liver, or intestines, or with inadequate fat digestion or absorption.

Article Source: http://www.live-article.com

Alien writes for Vitamins and Minerals . He also writes for vitamins world and you can get more information on Vitamin A .

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