Symmetry
Products with Vitamin A: NutraPack,
Mega Juice, Fruit-a-Mins, Premium Plus, Aloe Plus,
Extreme Fuel, Extreme Igniton & Recovery, Ultra
Vitality, Future Star, Symmetry Natural Facial Care
System
Vitamin
A was identified as a necessary growth factor in 1915
and was the first vitamin to be discovered. It is
obtained from food in a combination of two different
forms: as pre-formed vitamin A and as pro-vitamin
A, which the body can convert to vitamin A as necessary.
Pre-formed vitamin A, often in the form of retinal
or retinal, is found in foods of animal origin and
pro-vitamin A, of which beta-carotene is the best
known form, is found in orange, yellow and dark green
vegetables and fruits. Both forms are fat soluble.
What
does it do for your body?
EYES
- Vitamin A is essential for eyes to function
effectively. It is involved in the growth and
repair of the eye and in the production of a chemical
called visual purple, which helps in night vision.
EPITHELIAL CELLS - Vitamin A is involved in the
growth and repair of epithelial cells. These cells
cover the internal and external surfaces of the
body and are found in the skin, lungs, developing
teeth, inner ear, cornea of the eye, sex organs,
glands and their ducts, gums, nose, cervix and
other areas. This growth and maintenance role
is vital for many bodily functions. For example,
the good health of the digestive tract lining
is important in protecting against ulcers and
maintenance of the lining of the vagina and uterus
is important in fertility.
PREGNANCY - Vitamin A is necessary in pregnancy
for the development of the embryo.
NERVES - Vitamin A is involved in the production
of membranes and of myelin, which coats the nerves.
GLANDS AND HORMONES - Vitamin A plays a role in
the maintenance of the adrenal gland and synthesis
of certain hormones such as thyroid hormone.
THE IMMUNE SYSTEM - Vitamin A is known as "the
anti-infective vitamin" as it is vital for the
development of the body’s natural defenses. It
stimulates and enhances many immune functions.
This immune enhancing function promotes healing
of tissues and increases resistance to infection.
Adequate vitamin A intake, either from diet or
supplements, is very important especially for
children. Many studies have found that vitamin
A supplementation reduces the risk of infectious
diseases in areas where vitamin A deficiency is
widespread. A recent research review of several
studies found that adequate vitamin A intake in
children resulted in many health benefits.
Children in developing countries are often at
high risk of vitamin A deficiency. In developed
countries, ensuring adequate vitamin A intake
is particularly important for immune support.
GROWTH AND BONE FORMATION - Vitamin A is necessary
for growth and the formation of bones and teeth,
collagen synthesis, cartilage synthesis and wound
healing.
ANTIVIRAL ACTIVITY - Laboratory experiments have
shown vitamin A to have antiviral activity.
Absorption
The
presence of fat and bile in the intestines is
necessary for vitamin A absorption. Around 80
to 90 % of vitamin A in the diet is absorbed although
this is reduced in older people and those who
have trouble absorbing fat, such as pancreatitis,
celiac disease and cystic fibrosis sufferers,
who may run the risk of vitamin A deficiency.
Vitamin A is joined to fatty acids in the intestinal
lining, combined with other substances and transported
to the liver, which stores 90% of the body’s vitamin
A.
Deficiency
Vitamin
A deficiency is relatively rare in developed countries
and is usually limited to those who have absorption
difficulties, liver disease or who drink a lot
of alcohol. Vitamin A deficiency is common in
alcoholics and contributes to some of the disorders
of alcoholism such as night blindness, skin problems,
cirrhosis of the liver and susceptibility to infections.
Vitamin A deficiency symptoms:
EYES - One of the first symptoms of deficiency
is night blindness due to lack of visual purple.
Prolonged deficiency leads to xerophthalmia, a
condition in which eyes become dry, ulcers appear
on the cornea, the eyelids become swollen and
sticky and which eventually leads to blindness.
Vitamin A deficiency is the leading preventable
cause of blindness in developing countries.
SKIN - Prolonged deficiency leads to thickened
dry skin which is prone to infections. Small hardened
bumps of a protein known as keratin may develop
around the hair follicles.
GROWTH - Deficiency causes growth retardation,
weight loss, diarrhea, thickening of bone shafts,
congenital malformations, impaired hearing, taste
and smell, wasting of testicles and reduced sperm
count. Inadequate vitamin A intake may lead to
improper tooth formation in children and to gum
disease.
IMMUNE SYSTEM - Epithelial surfaces are adversely
affected by vitamin A deficiency causing increased
susceptibility to skin and respiratory infections.
Immune cells and antibody functions are also affected
which may lead to an increase in pre-cancerous
cells in the epithelial tissues of the mouth,
throat and lungs.
THYROID GLAND - A deficiency of vitamin A can
contribute to lower levels of active thyroid hormone
with symptoms of low body temperature, depression,
difficulty in losing weight, headaches and lethargy.
Therapeutic uses
Vitamin
A supplements are used in developing countries
to prevent or treat deficiency and to protect
immune system function.
SKIN DISORDERS - The vitamin A derivatives etretinate
and isotretinoin are used topically to treat psoriasis.
These compounds inhibit the formation of some
of the toxic compounds which may be responsible
for the high rate of cell division causing the
scaly build up on the skin.
Other Uses
Vitamin eye drops have been used to treat dry
eyes.
Creams containing vitamin A have been used to
heal wounds in patients taking corticosteroid
drugs.
Interactions
Vitamin E and zinc are necessary for vitamin A
metabolism, including absorption, transport and
release from the liver. Vitamin E may protect
against some of the effects of excess vitamin
A.
Vitamin A is necessary for calcium metabolism
in the formation of healthy bones and teeth.
Vitamin A absorption is reduced by mineral oil
laxatives, which bind it. Antacids, the anti-gout
drug colchicine, and the cholesterol reducing
drug, cholestyramine inhibit vitamin A absorption.
Alcohol irritates the digestive tract and inhibits
the absorption of vitamin A while also depleting
the body’s tissue stores.
Cautions
Pre-formed vitamin A supplements in doses of more
than 3000 mg RE should not be taken by women who
may become pregnant. Pro-vitamin A, or beta-carotene
are safe for pregnant women.
Vitamin A supplements should not be taken with
isotretinoin or etretinate for skin disease or
in cases of impaired liver or kidney function.
If vitamin A supplements are taken with large
amounts of alcohol, liver damage may occur.
Broad spectrum antibiotics should not be taken
with high doses of vitamin A.
The statements
on this web page have not been evaluated by the
Food and Drug Administration. Symmetry products
are not meant to diagnose, treat, cure or prevent
any disease. In all matters related to your health
please contact a qualified, licensed health practitioner. |