Vitamin E: benefits, dosage, deficiency
What are the benefits of vitamin E? How to get it and what dosage is recommended? Here's everything you need to know about this vitamin.
Origin
It was in 1922, at the University of California at Berkeley, that the embryologist Herbert McLean Evans found following an experiment on rats, that females following a diet depleted in lipids could not produce viable fetuses. They conclude that a fat-related compound is essential for the development of the fetus.
Then, in 1924, further studies conducted by Benett Sure at the University of Arkansas showed that a compound removed from the diet of male rats caused their sterility. Benett Sure calls it vitamin E.
In 1936, it was again Herbert McLean Evans who succeeded in isolating vitamin E from wheat germ oil.
It will then take 30 years for vitamin E to be recognized by the National Research Council of the United States as an essential nutrient for human health.
What is vitamin E used for?
Vitamin E is a substance that is found in 8 forms in nature: 4 tocopherols and 4 tocotrienols. The most common form is alpha-tocopherol. Vitamin E acts as an antioxidant. It neutralises the free radicals that destabilise the lipid molecules present in the cell membranes. These antioxidant properties are also used in the food industry: vitamin E is added to food to prevent the oxidation of fatty acids, a reaction is commonly known as "rancidity".
According to a 2012 study, gamma-tocopherol and tocotrienols help fight Alzheimer's disease. According to a 2010 study, they also prevent cirrhosis (caused by non-alcoholic fatty liver disease). Vitamin E has also been shown to be effective in the treatment of menstrual pain (2001 and 2005 studies in Tehran).
Thanks to its antioxidant effect, vitamin E helps to combat cataracts, arthritis and coronary diseases.
In addition, vitamin E has benefits for the skin: it delays ageing, makes the skin more supple and facilitates healing. For example, there are vitamin E face masks. Vitamin E is also beneficial for the health of the hair. In addition, vitamin E, together with other vitamins A, C and D, helps to maintain good hearing.
How much vitamin E do we need?
Here is the satisfactory intake (AI) of vitamin E published by the Anses (National Agency for Food, Environmental and Occupational Health Safety), according to sex and age, in milligrams per day:
- children under 6 months: 4 mg/d ;
- children aged 6 months and over: 5 mg/d ;
- children aged 1 to 3 years: 7 mg/d;
- children aged 4-6 years: 7 mg/d;
- children 7 to 10 years: 9 mg/d ;
- adolescents 11-14 years: 10 mg/d;
- adolescents 15-17 years: 10 mg/d;
- adolescent girls 15-17 years: 8 mg/d;
- men 18 years and older: 10 mg/d;
- women 18 years and older: 9 mg/d;
- pregnant women: 9 mg/d;
- breastfeeding women: 9 mg/d.
What are the signs of vitamin E deficiency?
Vitamin E deficiency is very rare and only occurs after several years without intake. It occurs mainly in people with diseases characterised by poor fat absorption, such as Crohn's disease, celiac disease and cystic fibrosis. Symptoms of vitamin E deficiency are burning in the feet and hands and neurological problems (impaired reflexes and muscle weakness).
In infants, vitamin E deficiency can lead to a form of haemolytic anaemia and muscle weakness. Premature babies can suffer from haemorrhages in the brain and abnormal growth of blood vessels in the eyes (retinopathy of prematurity).
What foods are rich in vitamin E?
Natural vitamin E is present in certain oils: wheat germ oil, argan oil, sunflower oil, avocado oil, rapeseed oil, almond oil, safflower oil, cottonseed oil, etc. Other sources of vitamin E include dried soya, peanuts, almonds, sunflower seeds, spinach, paprika and tuna.
Where to find vitamin E?
Vitamin E in the diet is usually sufficient to meet the body's needs. It is therefore not recommended to take supplements. However, vitamin E is available in the form of gel capsules, capsules, tablets or liquid for drip dosing. These supplements can be synthetic (dl-alpha) or made from oil naturally rich in vitamin E (dl-alpha-tocopherol). Natural vitamin E is more expensive but more potent and easier to absorb than the synthetic form. Some products can be bought online without a prescription, others are available from pharmacies on prescription, such as injectable solutions.Cosmetic vitamin E is also widely available in oil form. Thanks to its antioxidant action, it allows better preservation of preparations (balms, creams, care oils, massage oils...), but also delays skin ageing, cares for dehydrated skin and provides after-sun care. Natural organic vitamin E is produced from organic vegetable oils. It is available in organic shops and online shops.
What are the dangers of overdosing?
Food supplements provide between 1.5 and 1,500 IU of vitamin E per day. Doses of 400 IU are considered high. It is recommended not to exceed 1500 IU (1000 mg) per day. The dosage, therefore, depends on the vitamin E content in the capsule or tablet. For example, a vitamin E capsule of 200 IU (international units) or 134 mg would be taken once a day.Too high a dose of vitamin E can cause digestive problems, headaches, fatigue, chest pain, increased blood pressure and emotional disturbances. The risk of stroke may increase when taking at least 75 IU (international units) of vitamin E per day for several months.
The use of vitamin E supplements is not recommended for people taking anticoagulants, anti-tuberculosis, anticonvulsants and fat-reducing drugs. In addition, vitamin E should not be taken with food supplements that contain garlic, Ginkgo Biloba, onion or ginseng.
The French health authorities advise against the use of supplements containing vitamin E and selenium. Indeed, a 2014 study by the Fred Hutchinson Cancer Research Center published in the Journal of the National Cancer Institute shows that these supplements increase the risk of developing prostate cancer.