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The Function of Vitamin A in the Body
The main function of vitamin A is to supply essential nutrient to keep our eyesight keen, healthy skin and a strong immune system. Consequently, our body needs adequate levels of vitamin A to ensure the prevention of various eye problems, a number of skin disorder and a wide range of infections.
What is Vitamin A
Vitamin A, a fat-soluble nutrient, is stored in the liver. The body gets part of its vitamin A from animal fats and makes part in the intestine from beta-carotene and other carotenoids in fruit and vegetables. In our body vitamin A is present in various chemical forms called retinoids — so named because the vitamin is essential to the health of the retina.
The Function of Vitamin A
This vitamin prevents night blindness, maintains the skin and cells that line the respiratory and gastrointestinal tracts and helps to build teeth and bones. It is very important for our body for its reproduction, growth as well as development. In addition, vitamin A is crucial to the immune system, including the plentiful supply of immune cells that line the airways and digestive tract and form an important line of defence against disease.
Common Functions
- Helps the body to fight colds, flu and other types of infections.
- Promotes skin health and healing of wounds, burns and ulcers.
- Maintains healthy eyes.
- Benefits of the lining of the digestive tract.
Form
- Capsule
- Liquid
- Softgel
- Tablet
MAJOR BENEFITS:
Vitamin A is known for its ability to maintain our vision, especially at night, assisting the eye in adjusting from bright light to darkness. It can also alleviate ‘dry eye’, a complaint which is common in many developing countries and is specifically associated with severe vitamin A deficiency.
The function of vitamin A in the body is that it can boost immunity, vitamin A greatly strengthens resistance to infections, including sore throat, colds, flu and bronchitis. It may also combat cold sores and shingles (caused by a herpes virus), warts(a viral skin infection), eye infections and vaginal yeast infections —and perhaps even help to control allergies. The vitamin may help the immune system to battle against breast and lung cancers and improve survival rates in those with leukaemia; in addition, animal studies suggest it inhibits melanoma, a deadly form of skin cancer. Another benefit for cancer patients is that the effectiveness of chemotherapy may be enhanced when the body has good levels of vitamin A.
ADDITIONAL BENEFITS:
Vitamin A was first used in the 1940s to treat skin disorders, including acne and psoriasis, but the doses were high and toxic. Later scientists developed safer vitamin A derivatives (notably retinoic acid); it is now sold as prescription drugs as well as retinol cream, these include the acne and antiwrinkle cream Retin-A. Lower doses of vitamin A (7500 mcg a day) can be used, but only under the supervision of a doctor, to treat a range of skin conditions, including acne, dry skin, eczema, rosacea and psoriasis. When vitamin A levels in the body are good, the healing of skin wounds is promoted, and even recovery from sprains and strains
may be hastened. The value of good vitamin A levels even extends to the lining of the digestive tract, where it helps to treat inflammatory bowel disease and ulcers. In addition, getting enough of this vitamin will speed up recovery in people who have had strokes. Any women who got heavy or prolonged menstrual periods are sometimes deficient in vitamin A.
How much you need
The recommended target for vitamin A is 600 mcg a day for women and 700 mcg a day for men.
IF YOU GET TOO LITTLE: Although quite rare in the UK, a vitamin A deficiency can cause night blindness (even total blindness) and a greatly lowered resistance to infection. Milder cases of deficiency do occur, especially in the elderly, who often have vitamin-poor diets.
IF YOU GET TOO MUCH: Although levels of up to 1500 mcg a day are safe, supplementation with vitamin A should not be undertaken unless prescribed by a doctor. This advice is particularly important for women who are pregnant or are likely to become pregnant, because of the risk of damage to the developing foetus. Above these levels, an overabundance of vitamin A can be a real problem. A single dose of 150,000 mcg may induce weakness and vomiting, and as little as 7500 mcg a day for six years has been reported to cause serious liver disease (cirrhosis). You will see the signs of toxicity that includes cracking skin, dry and brittle nails, hair that falls out easily, bleeding gums, weight loss, irritability, fatigue and nausea.
Caution:
- Vitamin A can build up to toxic levels, so be careful not to get too much, and remember that the beta-carotene form of the vitamin is safer.
- Women who are pregnant or considering pregnancy should not take more than 1500 mcg of vitamin A daily; higher doses may cause birth defects. It is important to practise effective birth control when taking doses higher than 1500 mcg and for at least a month afterwards
Recent Findings
Vitamin A shows promise in the treatment of diabetes In two recent studies, up t 7500 mcg of vitamin A daily improved insulin’s ability to control blood sugar. (Poor blood sugar control is a serious problem in people with diabetes.) A Brazilian study found that vitamin A may combat chronic lung diseases. After 30 days of taking supplements, men who received 1500 mcg a day could breathe better than those who were given a placebo. Online pharmacy without prescription has a user-friendly website interface. Everyone can use the online pharmacy page without exception. You can quickly find the necessary drug and place an order for it anywhere in the country. They give an opportunity of purchasing drugs that are not available. Delivery of the order to the pharmacy is very fast.
Facts & Tips
- Vitamin A is best taken in the form of beta-carotene. You cannot overdose on the vitamin by eating carotenoid¬rich fruits and vegetables, such as apricots, cantaloupe melons or leafy greens. Although the body converts some carotenoids to vitamin A, it makes only as much as it needs. Unless you eat a lot
of oily fish, it is not possible to get too much vitamin A from your daily diet. - Vitamin A doses can be given as international units (1U) rather than retinol equivalents (RE), which are given in mcg. One RE is equivalent to 3.3 IU.
- If you’re heading to the North Pole, watch what you eat: 110 grams of the polar bear liver contain an acutely toxic dose of vitamin A — more than 600,000 mcg.
How to take it
DOSAGE:
To avoid excessive intake of vitamin A it is advisable to take supplements containing no more than the recommended daily allowance of 800 mcg a day. Alternatively, take vitamin A in the form of mixed carotenoids.
GUIDELINES FOR USE:
Take supplements with food; a little fat in the diet aids absorption. Vitamin E and zinc help the body to use vitamin A, which in turn boosts absorption of iron from foods.
Other sources
Vitamin A is richly represented in fish, egg yolks, butter, offal such as liver (90 grams provide more than 2500 mcg), and fortified milk (check the label to be sure). Yellow, orange, red and dark green fruits and vegetables have large amounts of beta-carotene and many other carotenoids, which the body makes into vitamin A when needed.
