Vitamin A
What is vitamin A?
What does Vitamin A
do?
Major benefits
Additional skin
care benefits
How much do you need and daily recommended dosage
Foods that
contain and supply vitamin A and beta carotene
Buying Vitamin a
supplements
How to take
vitamin A supplements
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Vitamin A, also known
as retinol, is a fat-soluble nutrient stored in the
liver. Your body gets part of its vitamin A from animal
fats and makes part in the intestine from beta-carotene
and other carotenoids in fruits and vegetables. Vitamin
A is present in your body in various forms called
retinoids, which is so named because this vitamin is
essential to the health of the retina of the eye.
- prevents night
blindness and maintains eye health
- maintains the skin
and cells that line the respiratory and
gastrointestinal tracts
- treats skin
disorders
- heals wounds,
burns and ulcers
- helps build teeth
and bones
- eases inflammatory
bowel disease
- it is vital for
normal reproduction, growth and development
- crucial to the
immune system
Vitamin A is best known
for its ability to maintain vision, especially night
vision. It helps the eye adjust from bright light to
darkness. It can also alleviate dry eye.
By boosting the immune
system, vitamin A greatly strengthens resistance to
infections, including sore throat, colds, flu, and
bronchitis. It may also help to combat cold sores and
shingles (caused by herpes), warts (viral skin
infection), eye infections, and vaginal yeast
infections. It may even control allergies for some
people.
Vitamin A may help the
immune system battle against breast and lung cancers and
improve survival rates in those with leukemia. In
addition, animal studies suggest that vitamin A inhibits
melanoma, a deadly form of skin cancer. Another benefit
for cancer patients is that vitamin A may enhance the
effectiveness of chemotherapy.
Vitamin A was first
used in the 1940's to treat skin disorders but the doses
were high and toxic. Safer forms of vitamin A
derivatives were later developed, notably retinoic acid
which includes the acne and antiwrinkle cream Retin-A.
Lower doses of vitamin
A (25,000 IU a day) can be used to treat a range of skin
conditions, including acne, dry skin, eczema, rosacea,
and psoriasis.
Vitamin A also promotes
healing of skin wounds and can be applied to cuts,
scrapes and burns. It may speed up recovery from sprains
and strains.
Women with heavy or
prolonged menstrual periods are sometimes deficient in
Vitamin A, so supplements may be of value in treating
this condition as well.
The RNI for vitamin A
is about 2,600 IU (800 RE - retinol equivalents) a day
for women, and 3,300 IU (1,000 RE) a day for men.
Higher doses are typically given for specific conditions
for a short time.
You can't overdose on
vitamin A from eating carotenoid-rich fruits and
vegetables because your body converts only as much as it
needs. Unless you eat a lot of liver or oily fish, it's
almost impossible to get too much vitamin A from your
diet. However, vitamin A can build up to toxic levels,
so be careful not to get too much. Before taking
vitamin A supplements, make sure you don't get the
required daily dosage from your diet first, or talk with
your doctor. Never, ever diagnose yourself!
Signs of overdose or
toxicity include dry, cracking skin and brittle nails,
hair that falls out easily, bleeding gums, weight loss,
irritability, fatigue, and nausea.
- fish
- egg yolks
- butter
- organ meats such
as liver (3 ounces of liver = more than 9,000 UI)
- fortified milk
(check the label to be sure)
- dark green,
yellow, orange and red fruits and vegetables contain
large amounts of beta-carotene which the body turns
into vitamin A
Take vitamin A
supplements with food; a little fat in the diet aids
absorption. Vitamin E and zinc help he body use vitamin
A which in turn boosts absorption of iron from foods.
Multivitamins supply
vitamin A sometimes in the form of beta-carotene. For
specific complaints in adults, up to 10,000 IU per day
is generally safe for long-term use. As a broad
guideline, taking 25,000 IU a day can be safe for up to
a month. Pregnant women and those who want to get
pregnant should not exceed 5,000 IU a day.
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