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General Nutrition and Diet Facts

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Vitamin E Benefits

 

Vitamin E

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. Alpha-tocopherol (α-tocopherol) is the name of the most active form of vitamin E in humans. It is also a powerful biological antioxidant . 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.

Foods rich on Vitamin E

Vegetable oils, nuts, green leafy vegetables, and fortified cereals are common food sources of vitamin E
Table 1,shows the selected Food Sources of Vitamin E, suggests many food sources of vitamin E. Food values are listed in alpha-tocopherol equivalents (ATE) to account for the variation in biological activity of the different forms of vitamin E.
Table 1: Selected Food Sources of Vitamin E
FOOD Milligrams (mg) Alpha-tocopherol per serving Percent DV*
Wheat germ oil, 1 tablespoon 20.3 100
Almonds, dry roasted, 1 ounce 7.4 40
Sunflower seed kernels, dry roasted, 1 ounce 6.0 30
Sunflower oil, over 60% linoleic, 1 tablespoon 5.6 30
Safflower oil, over 70% oleic, 1 tablespoon 4.6 25
Hazelnuts, dry roasted, 1 ounce 4.3 20
Peanut butter, smooth style, vitamin and mineral fortified, 2 Tablespoons 4.2 20
Peanuts, dry roasted, 1 oz 2.2 10
Corn oil (salad or vegetable oil), 1 tablespoon 1.9 10
Spinach, frozen, chopped, boiled, ½ cup 1.6 6
Broccoli, frozen, chopped, boiled, ½ cup 1.2 6
Soybean oil, 1 tablespoon 1.3 6
Kiwi, 1 medium fruit without skin 1.1 6
Mango, raw, without refuse, ½ cup sliced 0.9 6
Spinach, raw, 1 cup 0.6 4

*DV = Daily Value.
DVs are reference numbers 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 20 mg ATE). 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.

Table 2: Recommended Dietary Allowances for Vitamin E for Children and Adults
Age(years) Children(mg/day) Men(mg/day) Women(mg/day) Pregnancy(mg/day) Lactation(mg/day)
1-3 6 mg(=9 IU) - - - -
4-8 7 mg(=10.5 IU) - - - -
9-13 - 11 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)

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 ATE and IUs (1 mg ATE vitamin E = 1.5 IU)

Table 3: Adequate Intake for Vitamin E for Infants
Age(months) Males and Females (mg/day)
0 to 6 4 mg(=6 IU)
7 to 12 5 mg (=7.5 IU)


Risks of Deficiency

Vitamin E deficiency is rare in humans. There are three specific situations when a vitamin E deficiency is likely to occur.

1. 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 ;
2. Individuals with rare genetic abnormalities in the alpha-tocopherol transfer protein are at risk of vitamin E deficiency ; and
3. Premature, very low birth weight infants (birth weights less than 1500 grams, or 3 pounds, 4 ounces) are at risk of vitamin E deficiency .

Blood levels of vitamin E may also be decreased with zinc deficiency. Vitamin E deficiency is usually characterized by neurological problems associated with nerve degeneration in hands and feet. 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 :

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 effects 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. 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.

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).

Very low birth weight infants may be deficient in vitamin E .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. 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.

Issues and Controversies

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. 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. Vitamin E also may help prevent the formation of blood clots, which could lead to a heart attack.

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. 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. 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.

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. A study of middle-aged male smokers, however, did not demonstrate any effect from vitamin E supplements on the incidence of cataract formation. 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.

Uses

Heart disease
Vitamin E helps prevent arteries from clogging by blocking the conversion of cholesterol into the waxy fat deposits called plaque that stick to blood vessel walls. Vitamin E also thins the blood, allowing for blood to flow more easily through arteries even when plaque is present. Studies in the last 10 years have reported beneficial results from use of vitamin E supplements as part of a prevention strategy for heart disease and other types of cardiovascular disease.
A large, important study of postmenopausal women, for example, suggested that vitamin E from foods may reduce the risk of death from stroke in postmenopausal women. The study results do not, however, support any need for supplementation with vitamin E or other antioxidant vitamins as part of a preventive strategy.
There is some evidence for the use of supplemental vitamin E as a treatment for atherosclerosis.

Cancer
While no firm conclusions can be drawn about vitamin E's ability to protect against cancer, it has been noted that people with cancer often have lower levels of vitamin E. Plus, population based trials (observing groups of people over long periods of time) suggest that diets rich in antioxidants, including vitamin E, may be connected to a reduced risk of certain types of cancer, such as colon cancer. Supplementation with vitamin E, though, does not appear to improve risk of cancer.
Laboratory studies have generally shown that vitamin E inhibits the growth of some cancers in test tubes and animals, particularly hormone responsive cancers such as breast and prostate. There is reason to believe, therefore, that, for these types of cancers at least, supplementation may prove beneficial for both prevention and treatment.
Researchers have pointed to the fact that the body's antioxidant defense system is complex, which suggests that focusing on one vitamin in isolation may not be the best approach. This may be why dietary forms of antioxidants, since they are generally taken together from foods, may be the best way to try to stave off cancer.

Photodermatitis
This condition involves an allergic type reaction to the UV rays of the sun. A study comparing treatment with vitamins C and E to no treatment found that the vitamin group became significantly less sensitive to the sun. Another study, also showed a protective effect of the combination of vitamins C and E to UV rays.
Osteoarthritis
A few studies suggest that vitamin E may be helpful in both the treatment (pain relief, increased joint mobility) and prevention (at least in men) of osteoarthritis. In a study comparing vitamin E with diclofenac, a non-steroidal anti-inflammatory drug (NSAID) used to treat osteoarthritis, the two were found to be equally effective.

Alzheimer's Disease
There are several reasons why vitamin E might help treat Alzheimer's disease. The fat soluble vitamin readily enters the brain and exerts its antioxidative properties. Oxidative stress is believed to contribute to the development of Alzheimer's disease; therefore, again, it makes at least theoretical sense that antioxidants, like vitamin E, help prevent this condition. In fact, studies have suggested that vitamin E supplementation improves cognitive performance in healthy individuals and in those with dementia from causes other than Alzheimer's (for example, multiple strokes). In addition, vitamin E, together with vitamin C may prevent the development of Alzheimer's disease.

Menopause
According to a review article on alternatives to hormone replacement therapy (HRT) for women with breast cancer, vitamin E is the most effective option for the reduction of hot flashes for this group of women. Presumably, this would be true for other women not taking HRT because they cannot or prefer not to. Vitamin E also helps reduce other long term risks associated with menopause such as Alzheimer's, macular degeneration and cardiovascular disease.

Eye Health
Because of it's antioxidant action, vitamin E may help to protect against cataracts (clouding of the lens of the eye) and age related macular degeneration (ARMD, a progressive deterioration in the retina, the back part, of the eye). Both of these eye disorders tend to occur as people age. These conditions seriously compromise eyesight.Research reviews advocate diets high in vitamins C and E and carotenoids, especially spinach, kale, and collard greens. Taking supplements as a preventive measure, as opposed to getting vitamin E from food sources, remains controversial.
Uveitis is another eye disorder for which the antioxidant vitamins C and E may be helpful. A study of 130 patients with uveitis compared treatment with oral vitamins C and E to placebo and found that those who took the vitamins had significantly better visual clarity than those in the placebo group. Uveitis is inflammation of the uvea, the middle layer of the eye between the sclera (white outer coat of the eye) and the retina (the back of the eye). The uvea contains many of the blood vessels that nourish the eye. Inflammation of this area, therefore, can affect the cornea, the retina, the sclera, and other important parts of the eye. Uveitis occurs in acute and chronic forms.

Diabetes
People with diabetes tend to have low levels of antioxidants. Vitamin E supplements and other antioxidants may help reduce the risk of heart disease and other complications in people with diabetes. In particular, antioxidants have been shown to help control blood sugar levels, to lower cholesterol levels in those with type 2 diabetes, and to protect against the complications of retinopathy (eye damage) and nephropathy (kidney damage) in those with type 1 diabetes.

Pancreatitis
Oxidative stress plays a role in pancreatitis (inflammation of the pancreas). In fact, those with pancreatitis have low levels of vitamin E and other antioxidants. This may be due to lack of absorption of fat soluble vitamins (such as vitamin E) because the enzymes from the pancreas required to absorb fat are not functioning properly. Or, this may be due to poor intake because those with pancreatitis are not eating due to pain and need for bowel rest. Some experts relay that taking vitamin E and other antioxidants may help to reduce the pain and inflammation associated with pancreatitis.

Other
Vitamin E, along with other standard treatments, may also be beneficial for the following:
· Slowing the aging of cells and tissues
· Protecting from frostbite and other cold-induced injuries
· Diminishing the negative effects of environmental pollutants
· Improving anemia
· Speeding wound and burn healing
· Reducing scarring
· Lowering blood pressure
· Slowing progression of Parkinson's disease
· Easing premenstrual discomfort, especially breast tenderness
· Treating lupus
· Replacing necessary nutrients in those with inflammatory bowel disease, such as ulcerative colitis
· Avoiding miscarriage (also called spontaneous abortion), which may be associated with very low levels of this nutrient
· Helping weight gain and relieving oxidative stress in those with HIV or AIDS

How to Take

Based on clinical trials, the recommended dose for disease prevention and treatment for adults is 400 to 800 IU/day. As with all supplements, it is important to check with a healthcare provider before giving vitamin E to a child.
Daily intakes of dietary Vitamin E are listed below.
Note: 1 mg vitamin E equals 1.5 IU.
Pediatric
· Newborn to 6 months: 6 IU
· Infants 6 months to 1 year: 9 IU
· Children 1 to 3 years: 9 IU
· Children 4 to 8 years: 10.5 IU
· Children 9 to 13 years: 16.5 IU
· Adolescents 14 to 18 years: 22.5 IU

Adult
· Older than 18 years: 22.5 IU
· Pregnant females: 22.5 IU
· Breastfeeding females: 28.5 IU

Precautions

Because of the potential for side effects and interactions with medications, dietary supplements should be taken only under the supervision of a knowledgeable healthcare provider.
Vitamin E should be taken together with another antioxidant called selenium.
The Tolerable Upper Intake Limit (UL) for alpha-tocopherol is set at 1000 mg (1500 IU). Doses higher than this can cause nausea, gas, diarrhea, heart palpitations, and increase the tendency to bleed.
It is especially important that those who have high blood pressure or who are taking blood-thinners such as warfarin check with a healthcare provider before taking vitamin E supplements.
There is some concern that a diet rich in fish oil taken for many months may induce a deficiency of vitamin E. People who eat a diet high in fish or who take fish oil supplements may want to consider taking vitamin E supplements.

Possible Interactions
If you are currently being treated with any of the following medications, you should not use vitamin E supplements without first talking to your healthcare provider.
Antidepressant Medications, Tricyclic
Vitamin E inhibits the uptake by cells of the antidepressant desimpramine, which belongs to a class of drugs known as tricyclics. Other members of that class include imipramine and nortriptyline.
Antipsychotic Medications
Vitamin E can inhibit the uptake by cells of the antipsychotic medication called chlorpromazine, which belongs to a class of drugs known as phenothiazines.
Aspirin
A study evaluating the effects of vitamin E and aspirin suggests that the combination appears to be safe and may benefit patients at risk for stroke.
AZT
Vitamin E may protect against toxicity and side effects from AZT, a medication used to treat HIV and AIDS.
Beta Blockers for high blood pressure
Vitamin E inhibits the uptake by cells of propranolol, a member of a class of medications called beta blockers used for high blood pressure. Other beta-blockers include atenolol and metoprolol.
Birth Control Medications
Vitamin E may provide antioxidant benefits to women taking birth control medications.
Chloroquine
Vitamin E can inhibit the uptake into cells of chloroquine, a medication used to treat malaria.
Cholesterol-lowering Medications
Cholesterol-lowering medications such as colestipol and cholestyramine, called bile-acid sequestrants, decrease the absorption of vitamin E. Gemfibrozil, a different type of cholesterol-lowering medication called a fibric acid derivative, may also reduce vitamin E levels. A third class of medications used to lower cholesterol levels known as statins (such as atorvastatin, pravastatin, and lovastatin), may reduce the antioxidant activity of vitamin E. On the other hand, the combination of vitamin E supplements with statins may help protect blood vessels from dysfunction.
Cyclosporine
Vitamin E may interact with cyclosporine, a medication used to treat cancer, reducing the effectiveness of both the supplement and the medication. However, there appears to be some controversy regarding the nature of this interaction; another study suggests that the combination of vitamin E and cyclosporine may actually increase the effects of the medication. More research is needed to determine the safety of this combination.
Hormone Replacement Therapy
Vitamin E supplements may benefit women taking hormone replacement therapy by improving lipid profiles.
Mebendazole
Simultaneous supplementation with vitamins A, C, E, and selenium significantly reduced the effectiveness of this vermifuge (treatment to eradicate intestinal worms) in a study.
Tamoxifen
Tamoxifen, a hormonal treatment for breast cancer, increases blood levels of triglycerides, increasing one's chances of developing high cholesterol. In a study of 54 women with breast cancer, vitamins C and E, taken along with the tamoxifen, counteracted this by decreasing low density cholesterol and triglyceride levels while increasing high density cholesterol. The antioxidants also enhanced the anti-cancer action of the tamoxifen.
Warfarin
Taking vitamin E at the same time as warfarin, a blood-thinning medication, increases the risk of abnormal bleeding, especially in vitamin K-deficient individuals.
Weight Loss Products
Orlistat, a medication used for weight loss and olestra, a substance added to certain food products, are both intended to bind to fat and prevent the absorption of fat and the associated calories. Because of their effects on fat, orlistat and olestra may also prevent the absorption of fat-soluble vitamins such as vitamin E. Given this concern and possibility, the Food and Drug Administration (FDA) now requires that vitamin E and other fat soluble vitamins (namely, A, D, and K) be added to food products containing olestra. How well vitamin E from such food products is absorbed and used by the body is not clear. In addition, physicians who prescribe orlistat may add a multivitamin with fat soluble vitamins to the regimen.

 


 
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