Quais são os benefícios da vitamina E?

If you're eating a balanced and healthy diet, you're likely to be getting all the vitamin E benefits your body needs.

Dietitians Helen Bond and Clare Thornton-Wood from the British Dietetic Association (BDA) explain what vitamin E is and why your body needs it.

What is vitamin E?

Like most vitamins, vitamin E is a fat-soluble compound. Fat soluble vitamins are absorbed along with fats in the diet and are stored in your body's fatty tissue and liver.

Thornton-Wood says one of vitamin E’s key roles is as an antioxidant, helping protect your body’s cells from damage caused by unstable molecules - known as free radicals.

"These are produced by pollutants such as cigarette smoke, air pollution, and UV rays from the sun, and also by your body itself when food is digested," she explains.

"For this reason, vitamin E is important for maintaining a healthy immune system and overall health and wellbeing."

Like all things good for you, vitamin E is found in many healthy foods. If your body is not getting enough vitamin E - it's usually linked to a poor diet.

Bond notes that most people are able to get enough vitamin E in their diet.

"It can also be stored in the body, so it's not essential to be consumed in large amounts every day," she says. "So, a deficiency is rare in this country, even in people with a chronic malabsorption of fats - a condition where your body can't absorb fats properly."

In the UK it is recommended adults consume 3-15 milligrams of vitamin E daily.

What foods contain vitamin E?

"It is not difficult to obtain all the vitamin E benefits you need each day from eating a balanced diet," she adds. "Any not utilised that day can be stored by your body for future use."

While deficiency in vitamin E isn't likely, there are some people more prone to vitamin deficiency in general and in need of a higher intake of vitamin E.

Thornton-Wood explains that vitamin E deficiency is rare and is generally linked to diseases where digestion or absorption of fat is an issue - such as in Doença de Crohn e fibrose cística.

"In extreme cases a lack of vitamin E can cause damage to your nerves and muscles," she says. "This could result in loss of feeling in your arms and legs, weakness of your muscles and issues with your vision.

"A lack of vitamin E could also lead to you having a weakened immune function."

Vitamin E supplements are generally not necessary for most people. Thornton-Wood advises that vitamin E is much better obtained from food.

"This will then provide a range of other nutrients such as fibra, and additional vitamins and minerals," she says.

Bond adds that while there have been suggestions of health benefits linked to high doses of vitamin E, the jury is still out on whether supplementing with vitamin E is necessary.

She notes: "High doses of vitamin E have been implicated in promoting health and protecting against many health conditions including doença de Alzheimer.

"But so far there's not enough conclusive evidence that taking high doses of vitamin E supplements each day is essential. Instead, the effort should be on eating a healthy, balanced, and varied diet, and including plenty of foods that are naturally rich in vitamin E."

Like all things in life, you can end up with too much vitamin E, although it's extremely rare.

Thornton-Wood warns that extreme amounts of vitamin E can increase your chance of bleeding because they reduce your blood’s ability to clot properly. For this reason, if you are about to have surgery - you should not be taking vitamin E supplements.

"People on other medicines should always consult a pharmacist before taking dietary supplements," says Thornton-Wood. "In particular, vitamin E can interfere with the action of drugs such as varfarina - a type of blood thinner - and also the action of some chemotherapy drugs."