What you need to know about Vitamin E.

Vitamin E is a natural active ingredient first identified in 1922 by Herbert EVANS and Katharine BISHOP during their research on sterility. Subsequent studies on this compound concluded that it was essential for fertility. Vitamin E was then given the name tocopherol, from the Greek tokos: offspring and pherein: to bear. Its chemical structure was determined in 1938 by Erhard FERNHOLZ.

Contrary to what is sometimes believed, vitamin E is a family of liposoluble molecules, meaning they are capable of dissolving in fats. It encompasses 4 tocopherols and 4 tocotrienols, whose semi-developed formulas are presented below. Among these compounds, it is often alpha-tocopherol that is found in dietary supplements or used to formulate cosmetic products. There are two reasons for this: this form is particularly stable and it is the most biologically active molecule.

As the body does not synthesise Vitamin E, it is essential to provide it through diet. The foods containing the most Vitamin E are vegetable oils such as wheat germ oil, soybean oil, sunflower oil, and olive oil. Oilseeds like walnuts, almonds, and hazelnuts are also rich in Vitamin E, as are certain vegetables like spinach and asparagus. Among fruits, the avocado stands out. Once consumed, the body stores Vitamin E, particularly in the sebaceous glands of the dermis. The Vitamin E then reaches the epidermis via the sebum flow, a greasy secretion that protects and hydrates the skin.

Note : It is rare to be deficient in vitamin E and this condition is usually due to fat absorption disorders or certain genetic diseases. A deficiency is characterised by pain in the hands and feet, associated with a loss of osteotendinous reflexes and muscle weakness.

There are two main methods of obtaining vitamin E : extraction from vegetable oils and chemical synthesis in a laboratory. The former typically involves the use of soybean oil and/or sunflower oil, which are very rich in tocopherols. The extraction is carried out using an organic solvent, most often hexane in which vitamin E is soluble. It concludes with several stages of purification, allowing for a purer molecule to be obtained. This first method is the most commonly used, due to cost and technical reasons.

The laboratory synthesis, on the other hand, requires hydroquinone, a natural precursor of tocopherols derived from a molecule found in the chlorophyll of plants. Several steps are required to achieve the formation of vitamin E, including alkylations, methylations and hydroxylations. The synthesis also concludes with the isolation and purification of the final compound.

The vitamin E is primarily known for its antioxidant effects, benefiting the body, skin, and hair alike. Indeed, it protects the various cells of the body from oxidative stress induced by external aggressions such as the sun, pollution, or even tobacco. The excessive generation of free radicals damages lipids, proteins, and DNA, leading to an acceleration of cellular ageing. As a result, vitamin E is often used in cosmetics to slow down skin sagging, the appearance of white hair and hair loss. However, its benefits do not stop there:

• Vitamin E stimulates blood circulation.

  Vitamin E also promotes cellular renewal and supports the anagen phase, or hair growth phase, thanks to its vasodilatory properties. Indeed, this molecule can stimulate the production of nitric oxide (NO) by the endothelial cells of the blood vessels, which causes a relaxation of the smooth muscles of the vessels and promotes blood flow. This property of vitamin E is also useful in case of a feeling of heavy legs.

• Vitamin E has anti-inflammatory properties.

  Vitamin E can also inhibit certain inflammatory processes such as the NF-κB and JAK-STAT6 signalling pathways, involved in the production of cytokines and chemokines. Several studies conducted with patients suffering from acne or psoriasis, inflammatory dermatoses, have obtained encouraging results following the oral intake of vitamin E. As for its topical application, the evidence is still lacking.

• Vitamin E can alleviate hyperpigmentation.

  Brown spots are a very common skin issue that is difficult to tackle. Although it's not a miracle solution, vitamin E appears to be able to reduce their appearance, when taken orally and/or applied topically. Its effectiveness is based on its ability to suppress the activity of tyrosinase, the enzyme that catalyses the production of melanin. For enhanced action, it is recommended to combine vitamin E with vitamin C, which also has depigmenting properties.

• Vitamin E to preserve oil-based formulations.

  Even though it is not legally possible to classify vitamin E as a preservative, its antioxidant properties enable it to prevent the oxidation of oily cosmetic formulas. It thus protects these from air oxygen and UV rays, preventing them from losing quality and effectiveness, or even becoming comedogenic.

Vitamin E is essential for the proper functioning of the body. In adults, the recommended daily nutritional intake is 12 mg, this figure varies slightly depending on the individual's sex and weight. Cases of overdose (> 1000 mg/day) are rare but can lead to digestive disorders, migraines, fatigue, chest pain or even an increase in blood pressure. Due to its vasodilatory properties, the intake of vitamin E is not recommended for patients taking anticoagulants or those who have had a stroke.

Generally, it is not recommended to take dietary supplements without medical supervision.

With regards to the vitamin E found in cosmetics, it is a gentle active ingredient often used at concentrations less than 0.5%. In 2014, the CIR (Cosmetic Ingredient Review) concluded its safety in skincare when incorporated at concentrations of 0.5% or less. These results concern not only tocopherol but also the following derivatives, which are sometimes found in cosmetics: ascorbyl tocopheryl acetate, ascorbyl tocopheryl maleate, dioleyl tocopheryl, methylsilanol, potassium ascorbyl tocopheryl phosphate, sodium tocopheryl phosphate, tocophersolan, tocopheryl acetate, tocopheryl linoleate, tocopheryl linoleate/oleate, tocopheryl nicotinate tocopheryl phosphate tocopheryl succinate, tocotrienols.

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• JIALAL I. & al. Vitamin E, Oxidative Stress and Inflammation. Annual Review of Nutrition (2005).

• NETSCHER T. Synthesis of Vitamin E. Vitamins & Hormones (2007).

• Cosmetic Ingredient Review: Safety Evaluation of Tocopherols and Tocotrienols as Utilised in Cosmetics (2014).

• ERKEKOGLU P., SANTOS S. & BLUMENBERG M. Vitamin E in Health and Disease: Interactions, Diseases and Health Aspects. Biochemistry (2021).

• Mohammed GUIGA's Thesis. Vitamin E: Metabolism, Physiological Role: Benefits and Risks of Supplementation (2021).