20080214

Older, Active and Vitamin E

In older people, low vitamin E concentration contributes to decline in physical function. A study found this when it looked at data on about 700 Italians.

Benedetta Bartali of Yale University School of Medicine and her colleagues measured vitamin E in the blood and assessed the abilities to walk a short distance, stand up from a chair, and balance.

In people with low vitamin E, the odds of declining in physical function after three years were greater than in those with higher levels.

Her conclusion:

``An adequate level of vitamin E may reduce the decline in physical function.’’

Good sources of vitamin E include olive oil, almonds and sunflower seeds.

The study, named InCHIANTI, in the Journal of the American Medical Association, was supported in part by the National Institutes of Health.

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 (α-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.).

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.



The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies.

Copyright Information: Public domain information with acknowledgement given to the U.S. National Library of Medicine.

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