VITAMIN E......

VITAMIN E.............?

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Vitamin E is a fat-soluble vitamin. This means that it is dissolved in
fat. Vitamin E attaches to fat. This is how it is carried through the
body. This is one reason why moderate amounts of fat are needed in the
diet. The body can store fat-soluble vitamins. Vitamin E has strong
antioxidant properties. The vitamin may protect against heart disease and
cancer. Its protective role has been widely studied. Vitamin E is part of
a group of substances called tocopherols. Each group has different
potencies.
 
What food source is the nutrient found in?
Vitamin E is found in the fatty parts of foods. The best sources of
vitamin E are unsaturated fats, such as vegetable oils. These include
sunflower, safflower, canola, olive, and wheat germ oils.
avocados, nuts, seeds, wheat germ, and whole grain, or unrefined,
products.
Green leafy vegetables have smaller amounts.
Soybean oil has a form of vitamin E that has little influence on health.
This oil is not a good source of vitamin E. Soybean oil is the most
common oil used in products like salad dressing and mayonnaise.
Heating oils to high temperatures, such as in frying, can destroy vitamin
E. Storage and freezing foods for a long time can also destroy vitamin E.

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Vitamin E is found in the germ of a seed or grain. Most of the nutrients
are concentrated there. Whole-wheat flour contains much of the original
germ, so it has vitamin E. Refined flour, or white flour, has been
stripped of many of its nutrients, including vitamin E.
 
How does the nutrient affect the body?
Vitamin E is an important antioxidant. Antioxidants protect cells from
oxidation. Oxidation can lead to cell damage. Cell damage can lead to
chronic health problems, such as heart disease and cancer. Vitamin E
works closely with other antioxidants, like vitamin C and selenium, to
help protect the body. Vitamin E improves the way the body uses vitamin
A. It may help protect against ion the toxic effects of some metals, such
as lead.
 
Information
The recommended dietary allowances, or RDAs, for vitamin E were recently
changed. They were increased to provide maximum health benefits. Levels
were raised from 10 milligrams (mg) daily to 15 mg daily for adult men
and women. Pregnancy increases the recommendations slightly. It is
difficult to get enough vitamin E from food alone. To get the full
benefit of vitamin E, a supplement is recommended. The government
estimates that 68 percent of men and 71 percent of women do not get
enough vitamin E daily.
 
An upper level, based only on intake from vitamin supplements has been
set at 1,000 mg of alpha-tocopherol. This is the most potent form of
vitamin E. The upper level is not the recommended amount to take. The
upper level is the maximum intake of a vitamin or mineral that is likely
to cause no health risks. People should not routinely go above the set
upper levels for vitamins and minerals. Taking too much vitamin E puts
people at risk for prolonged bleeding time. This is because large doses
can interfere with vitamin K. Vitamin K helps the blood to clot when a
person is bleeding. Not enough is known about vitamin E to make positive
claims on mega doses, or extremely high doses of the vitamin. The
question is if mega doses of antioxidants, such as vitamin E, can
decrease the risk for chronic diseases. More research is needed.
 
Severe vitamin E deficiency is rare. Conditions where it may occur
include people who don't absorb fat normally, premature infants, people
with red blood cell disorders, and people on kidney dialysis. Symptoms of
vitamin E deficiency include nerve damage and anemia in infants.
 
To maximize vitamin E intake, healthy vegetable oils, nuts, seeds, and
unrefined whole-grain products should be a regular part of the diet.
 

 

Vitamin E: What is it?
Vitamin E is a fat-soluble vitamin that exists in eight different forms.
Each form has its own biological activity, which is the measure of
potency or functional use in the body [1]. Alpha-tocopherol
(á-tocopherol) is the name of the most active form of vitamin E in
humans. It is also a powerful biological antioxidant [2-3]. Vitamin E in
supplements is usually sold as alpha-tocopheryl acetate, a form of
alpha-tocopherol that protects its ability to function as an antioxidant.
The synthetic form is labeled "D, L" while the natural form is labeled
"D". The synthetic form is only half as active as the natural form [4].

Antioxidants such as vitamin E act to protect your cells against the
effects of free radicals, which are potentially damaging by-products of
energy metabolism. Free radicals can damage cells and may contribute to
the development of cardiovascular disease and cancer. Studies are
underway to determine whether vitamin E, through its ability to limit
production of free radicals, might help prevent or delay the development
of those chronic diseases. Vitamin E has also been shown to play a role
in immune function, in DNA repair, and other metabolic processes [2-3].

What foods provide vitamin E?
Vegetable oils, nuts, green leafy vegetables, and fortified cereals are
common food sources of vitamin E in the United States (U.S.). Table 1,
Selected Food Sources of Vitamin E, suggests many food sources of vitamin
E [4]. Food values are listed in the alpha-tocopherol form of vitamin E.

Table 1: Selected Food Sources of Vitamin E [4] FOODMilligrams (mg)
Alpha-tocopherol
per servingPercent
DV*
Wheat germ oil, 1 tablespoon20.3100
Almonds, dry roasted, 1 ounce7.440
Sunflower seed kernels, dry roasted, 1 ounce6.030
Sunflower oil, over 60% linoleic, 1 tablespoon5.630
Safflower oil, over 70% oleic, 1 tablespoon4.625
Hazelnuts, dry roasted, 1 ounce4.320
Peanut butter, smooth style, vitamin and mineral fortified, 2
Tablespoons4.220
Peanuts, dry roasted, 1 oz2.210
Corn oil (salad or vegetable oil), 1 tablespoon1.910
Spinach, frozen, chopped, boiled, ½ cup1.66
Broccoli, frozen, chopped, boiled, ½ cup1.26
Soybean oil, 1 tablespoon1.36
Kiwi, 1 medium fruit without skin1.16
Mango, raw, without refuse, ½ cup sliced0.96
Spinach, raw, 1 cup0.64
*DV = Daily Value. DVs are reference numbers developed by the Food and
Drug Administration (FDA) to help consumers determine if a food contains
a lot or a little of a specific nutrient. The DV for vitamin E is 30
International Units (or about 20 mg alpha-tocopherol). Most food labels
do not list a food's vitamin E content. The percent DV (%DV) listed on
the table indicates the percentage of the DV provided in one serving. A
food providing 5% of the DV or less is a low source while a food that
provides 10-19% of the DV is a good source. A food that provides 20% or
more of the DV is high in that nutrient. It is important to remember that
foods that provide lower percentages of the DV also contribute to a
healthful diet. For foods not listed in this table, please refer to the
U.S. Department of Agriculture's Nutrient Database Web site:
http://www.nal.usda.gov/fnic/foodcomp/search/.

What is the recommended intake for vitamin E?
Recommendations for vitamin E are provided in the Dietary Reference
Intakes developed by the Institute of Medicine [5]. Dietary Reference
Intakes (DRIs) is the general term for a set of reference values used for
planning and assessing nutrient intake for healthy people. Three
important types of reference values included in the DRIs are Recommended
Dietary Allowances (RDA), Adequate Intakes (AI), and Tolerable Upper
Intake Levels (UL). The RDA recommends the average daily dietary intake
level that is sufficient to meet the nutrient requirements of nearly all
(97-98%) healthy individuals in each age and gender group [5]. An AI is
set when there is insufficient scientific data available to establish a
RDA. AIs meet or exceed the amount needed to maintain a nutritional state
of adequacy in nearly all members of a specific age and gender group. The
UL, on the other hand, is the maximum daily intake unlikely to result in
adverse health effects [5].

In Table 2, RDAs for vitamin E are based only on the alpha-tocopherol
form of vitamin E [5]. Table 2 also lists RDAs for vitamin E in
International Units (IU) because food and most supplement labels list
vitamin E content in International Units (1 mg alpha-tocopherol vitamin E
= 1.49 IU).

Table 2: Recommended Dietary Allowances for Vitamin E for Children and
Adults [5]
Age
(years)Children
(mg/day)Men
(mg/day)Women
(mg/day)Pregnancy
(mg/day)Lactation
(mg/day)
1-36 mg
(=9 IU)
4-87 mg
(=10.5 IU)
9-1311 mg
(=16.5 IU)11 mg
(=16.5 IU)15 mg
(=22.5 IU)19 mg
(=28.5 IU)
14 +15 mg
(=22.5 IU)15 mg
(=22.5 IU)15 mg
(=22.5 IU)19 mg
(=28.5 IU)

There is insufficient scientific data on vitamin E to establish an RDA
for infants. An Adequate Intake (AI) has been established that is based
on the amount of vitamin E consumed by healthy infants who are fed breast
milk. Table 2 lists the adequate intakes for vitamin E for infants in mg
alpha-tocopherol and IUs (1 mg alpha-tocopherol = 1.49 IU) [5].

Table 3: Adequate Intake for Vitamin E for Infants [5]
Age
(months)Males and Females
(mg/day)
0 to 64 mg
(=6 IU)
7 to 125 mg
(=7.5 IU)

Who is at risk for vitamin E deficiency?
Vitamin E deficiency is rare in humans. There are three specific
situations when a vitamin E deficiency is likely to occur.

persons who cannot absorb dietary fat due to an inability to secrete bile
or with rare disorders of fat metabolism are at risk of vitamin E
deficiency [8];
individuals with rare genetic abnormalities in the alpha-tocopherol
transfer protein are at risk of vitamin E deficiency [9]; and
premature, very low birth weight infants (birth weights less than 1500
grams, or 3 pounds, 4 ounces) are at risk of vitamin E deficiency [3,10].
Blood levels of vitamin E may also be decreased with zinc deficiency
[11]. Vitamin E deficiency is usually characterized by neurological
problems associated with nerve degeneration in hands and feet [5]. These
symptoms are also associated with other medical conditions. A physician
can determine if they are the result of a vitamin E deficiency or are
from another cause.

Who may need extra vitamin E to prevent a deficiency?
Individuals who cannot absorb fat require a vitamin E supplement because
some dietary fat is needed for the absorption of vitamin E from the
gastrointestinal tract. Intestinal disorders that often result in
malabsorption of vitamin E and may require vitamin E supplementation
include [3]:

Crohn's Disease is an inflammatory bowel disease that affects the small
intestines. People with Crohn's disease often experience diarrhea and
nutrient malabsorption.
Cystic Fibrosis is an inherited disease that affects the lungs,
gastrointestinal tract, pancreas, and liver. Cystic fibrosis can
interfere with normal digestion and absorption of nutrients, especially
of fat soluble vitamins including vitamin E.
People who cannot absorb fat often pass greasy stools or have chronic
diarrhea. People with an inability to secrete bile, a substance that
helps fat digestion, may need a special water-soluble form of vitamin E.

Abetalipoproteinemia is a rare inherited disorder of fat metabolism that
results in poor absorption of dietary fat and vitamin E [8]. The vitamin
E deficiency associated with this disease causes problems such as poor
transmission of nerve impulses, muscle weakness, and degeneration of the
retina that can cause blindness. Individuals with abetalipoproteinemia
may be prescribed special vitamin E supplements by a physician to treat
this disorder [12].

Ataxia and vitamin E deficiency (AVED) is also a rare inherited disorder.
It is caused by a genetic defect in a liver protein that is responsible
for maintaining normal alpha-tocopherol concentrations in the blood.
These individuals have such severe vitamin E deficiency that without
supplements they are unable to walk (ataxia) [9].

Very low birth weight infants may be deficient in vitamin E [3,10].
Necrotizing enterocolitits, a condition sometimes seen in very low birth
weight infants that is characterized by inflammation of the lining of the
intestines, may lead to a vitamin E deficiency [4]. These infants are
usually under the care of a neonatologist, a pediatrician specializing in
the care of newborns who evaluates and treats the exact nutritional needs
of premature infants.

What are some current issues and controversies about vitamin E?
Vitamin E and heart disease
Preliminary research has led to a widely held belief that vitamin E may
help prevent or delay coronary heart disease [13]. Researchers have
reported that oxidative changes to LDL-cholesterol (sometimes called
"bad" cholesterol) promote blockages (atherosclerosis) in coronary
arteries that may lead to heart attacks. Vitamin E may help prevent or
delay coronary heart disease by limiting the oxidation of LDL-cholesterol
[14]. Vitamin E also may help prevent the formation of blood clots, which
could lead to a heart attack. Observational studies have associated lower
rates of heart disease with higher vitamin E intake. A study of
approximately 90,000 nurses suggested that the incidence of heart disease
was 30% to 40% lower among nurses with the highest intake of vitamin E
from diet and supplements. Researchers found that the apparent benefit
was mainly associated with intake of vitamin E from dietary supplements.
High vitamin E intake from food was not associated with significant
cardiac risk reduction [15]. A 1994 review of 5,133 Finnish men and women
aged 30-69 years also suggested that increased dietary intake of vitamin
E was associated with decreased mortality (death) from heart disease
[16].

Even though these observations are promising, randomized clinical trials
raise questions about the efficacy of vitamin E supplements in the
prevention of heart disease. The Heart Outcomes Prevention Evaluation
(HOPE) Study followed almost 10,000 patients for 4.5 years who were at
high risk for heart attack or stroke [17]. In this intervention study the
subjects who received 265 mg (400 IU) of vitamin E daily did not
experience significantly fewer cardiovascular events or hospitalizations
for heart failure or chest pain when compared to those who received a
placebo (sugar pill). The researchers suggested that it is unlikely that
the vitamin E supplement provided any protection against cardiovascular
disease in the HOPE study. This study is continuing, with the goal of
determining whether a longer duration of intervention with vitamin E
supplements will provide any protection against cardiovascular disease.

In a study sponsored by the National Heart, Lung, and Blood Institute
(NHLBI) of the National Institutes of Health, postmenopausal women with
heart disease who took supplements providing 400 IU vitamin E and 500 mg
vitamin C twice a day, either alone or in combination with hormones, did
not have fewer heart attacks or deaths. There was also no change in
progression of their coronary disease. This study, The Women's
Angiographic Vitamin and Estrogen (WAVE) trial, studied 423
postmenopausal women at seven clinical centers in the U.S. and Canada. In
postmenopausal women with coronary disease enrolled in this trial,
neither hormone replacement therapy nor antioxidant vitamin supplements
provided cardiovascular benefit [18].

Vitamin E and cancer
Antioxidants such as vitamin E are believed to help protect cell
membranes against the damaging effects of free radicals, which may
contribute to the development of chronic diseases such as cancer [4].
Vitamin E also may block the formation of nitrosamines, which are
carcinogens formed in the stomach from nitrites consumed in the diet. It
also may protect against the development of cancers by enhancing immune
function [19]. Unfortunately, human trials and surveys that have tried to
associate vitamin E intake with incidence of cancer have been generally
inconclusive.

Some evidence associates higher intake of vitamin E with a decreased
incidence of prostate cancer and breast cancer [20]. However, an
examination of the effect of dietary factors, including vitamin E, on
incidence of postmenopausal breast cancer in over 18,000 women from New
York State did not associate a greater vitamin E intake with a reduced
risk of developing breast cancer [21].

A study of women in Iowa provides evidence that an increased dietary
intake of vitamin E may decrease the risk of colon cancer, especially in
women under 65 years of age [22]. On the other hand, a study of 87,998
females from the Nurses' Health Study and 47,344 males from the Health
Professionals Follow-up Study failed to support the theory that an
increased dietary intake of vitamin E may decrease the risk of colon
cancer [23].

The American Cancer society recently released the results of a long-term
study that evaluated the effect of regular use of vitamin C and vitamin E
supplements on bladder cancer mortality in almost 1,000,000 adults in the
U.S. The study, conducted between the years 1982 to 1998, found that
subjects who regularly consumed a vitamin E supplement for longer than 10
years had a reduced risk of death from bladder cancer. No benefit was
seen from vitamin C supplements [24].

At this time researchers cannot confidently recommend vitamin E
supplements for the prevention of cancer because the evidence on this
issue is inconsistent and limited.

Vitamin E and cataracts
Cataracts are abnormal growths in the lens of the eye. These growths
cloud vision. They also increase the risk of disability and blindness in
aging adults. Antioxidants are being studied to determine whether they
can help prevent or delay cataract growth. Observational studies have
found that lens clarity, which is used to diagnose cataracts, was better
in regular users of vitamin E supplements and in persons with higher
blood levels of vitamin E [25]. A study of middle-aged male smokers,
however, did not demonstrate any effect from vitamin E supplements on the
incidence of cataract formation [26]. The effects of smoking, a major
risk factor for developing cataracts, may have overridden any potential
benefit from the vitamin E, but the conflicting results also indicate a
need for further studies before researchers can confidently recommend
extra vitamin E for the prevention of cataracts.

What is the health risk of too much vitamin E?
Most studies of the safety of vitamin E supplementation have lasted for
several months or less, so there is little evidence for the long-term
safety of vitamin E supplementation.

The Food and Nutrition Board of the Institute of Medicine has set an
upper tolerable intake level (UL) for vitamin E at 1,000 mg (1,500 IU)
for any form of supplementary alpha-tocopherol per day. Based for the
most part on the result of animal studies, the Board decided that because
vitamin E can act as an anticoagulant and may increase the risk of
bleeding problems this UL is the highest dose unlikely to result in
bleeding problems.

Table 4 lists the Tolerable Upper Intake Levels (UL) of vitamin E in mg
alpha-tocopherol and IUs for children and adults (1 mg alpha-tocopherol
vitamin E = 1.49 IU). A UL for vitamin E for infants up to 12 months of
age has not been established.

Table 4: Tolerable Upper Intake Levels (UL) of vitamin E for Children and
Adults [5]
Age (years)Males
(mg/day)Females
(mg/day)Pregnancy
(mg/day)Lactation
(mg/day)
1-3200
(=300 IU)200
(=300 IU)N/AN/A

4-8300
(=450 IU)300
(=450 IU)N/AN/A

9-13600
(=900 IU)600
(=900 IU)N/AN/A
14-18800
(=1,200 IU)800
(=1,200 IU)800
(=1,200 IU)800
(=1,200 IU)
19-701,000
(=1,500 IU)1,000
(=1,500 IU)1,000
(=1,500 IU)1,000
(=1,500 IU)
> 701,000
(=1,500 IU)1,000
(=1,500 IU)N/A
(=1,500 IU)N/A
(=1,500 IU)

Vitamin E intakes and healthful diets
Many people are concerned about their fat intake today. Your overall diet
should be moderate in fat, but it is important to include some healthful
sources of fat, including those oils and nuts that provide vitamin E.
Including these foods in your diet will help you meet your daily need for
vitamin E. Meats, grain products, dairy products, and most fruits and
vegetables are generally not good sources of vitamin E. According to the
2005 Dietary Guidelines for Americans, "Nutrient needs should be met
primarily through consuming foods. Foods provide an array of nutrients
and other compounds that may have beneficial effects on health. In
certain cases, fortified foods and dietary supplements may be useful
sources of one or more nutrients that otherwise might be consumed in less
than recommended amounts. However, dietary supplements, while recommended
in some cases, cannot replace a healthful diet."

The Dietary Guidelines for Americans describes a healthy diet as one
that:
emphasizes a variety of fruits, vegetables, whole grains, and fat-free or
low-fat milk and milk products;
includes lean meats, poultry, fish, beans, eggs, and nuts;
is low in saturated fats, trans fats, cholesterol, salt (sodium), and
added sugars; and
stays within your daily calorie needs.

Functions and benefits of Vitamin E
Vitamin E has a number of important functions and benefits. For example
it:
Vitamin E is use to treat symptoms of Alzheimer's disease and reduce the
risk of heart disease and prevent leg muscle cramps.
Vitamin E is an antioxidant, that protects body tissue from damage caused
by unstable substances known as free radicals.
Vitamin E is also important in the formation of red blood cells and it
helps the body to use vitamin K.
Recommended Dosage for Vitamin E
For adults, the usual dose of Vitamin E is 200 IU (5 mcg ).
For Pregnant women, the usual dose is 400 IU (10 mcg ).
Food sources of Vitamin E
Foods sources of vitamin E include the following.
chickpeas
egg yolk
fats and oils
green leafy vegetables
olives
parsnips
red peppers
seeds
soy products and soya beans
carrots
Cheese, especially Parmesan, Cheddar
Deficiency Symptoms of Vita
muscle weakness loss of muscle mass abnormal eye movements impaired
vision Gait disturbances poor reflexes loss of position sense loss of
vibration sense shortened red blood cell life.