Everything you need to know about Vitamin C.

Also known asascorbic acid, vitamin C is essential for proper metabolic function but is not produced by the body. It is crucial to supply the body with it through diet (citrus fruits, chestnuts, spinach, peppers, strawberries...) and/or dietary supplements. According to health authorities, to maintain good health, it is important to consume about 200 mg per day. Vitamin C is vital as it stimulates the immune system as well as tissue repair and contributes to bone development. Moreover, a prolonged deficiency in ascorbic acid (about 3 months) can lead to a deadly disease called "scurvy", characterized by a significant hemorrhagic syndrome.

Several studies agree that the epidermis is often deficient in vitamin C ; the reason being that only 1/3 of this molecule absorbed by the body ends up in the skin. Moreover, when applied topically, vitamin C is much more effective for the skin than when it is ingested orally. Hence the success of cosmetic treatments formulated with this active ingredient.

In skincare, vitamin C is brimming with benefits; notably, it contributes to collagen production, brightens the complexion, and protects the skin from damage caused by sun exposure and harmful free radicals. Thus, this powerful antioxidant is found in many serums, facial cleansers, oils, and moisturizers. It also has excellent virtues for hair.

Pure vitamin C, also known as L-ascorbic acid, is the one that provides the best results in terms of overall skin and complexion improvement. However, its acidic pH around 3.5 must be maintained in a cosmetic formula to avoid oxidation problems.

This parameter can be restrictive, so some derivatives of vitamin C are used such as the "Magnesium Ascorbyl Phosphate", the "Sodium Ascorbyl Phosphate", "Ascorbyl Palmitate", the "Tetrahexyldecyl Ascorbate", "Ascorbyl Glucoside" or even the "3-O Ethyl Ascorbate".

When applied topically, vitamin C is far more effective than when ingested through diet.

• Antioxidant, it slows down skin aging. By acting at the epidermis level, it strengthens the skin barrier and neutralizes free radicals generated by pollution, stress, or sun exposure;

• It enhances the appearance of the dermis and epidermis by regulating excess melanin for a visibly luminous complexion;

• It boosts the production of keratinocytes in order to optimize skin elasticity and minimize pores;

• She reduces wrinkles by fighting against cell inflammation and by increasing the density of the dermal papillae;

• She hasimproved blood circulation and skin oxygenation to give a boost to the healing process and cellular renewal.

• It helps to reduce and prevent under-eye circles by strengthening the skin, which is generally thinner in this area of the face. Its action conceals the underlying blood vessels, visibly reducing puffiness.

• It accelerates the production of collagen, which is responsible for the firmness and elasticity of the skin.

Vitamin C is generally safe when consumed in foods or applied topically. However, individuals with sensitive skin or allergies may experience a yellowish discoloration. This phenomenon is particularly noticeable on dry, dehydrated, or sensitive skin, which tends to react poorly to acidic pH levels. Although rare, these individuals may experience irritations such as tingling, itching, and dryness after using vitamin C in skincare. This issue can be addressed by layering a moisturizer over the vitamin C treatment you are using. If you have sensitive skin, it is recommended to start with a low concentration of vitamin C to monitor any potential skin reactions. In all cases, it is important to test vitamin C before incorporating it into your daily beauty routine.

• OHSGIMA H. & al. Effects of vitamin C on dark circles of the lower eyelids: quantitative evaluation using image analysis and echogram. Skin Research and Technology (2009).

• TELANG P. S. Vitamin C in dermatology. Indian Dermatology Online Journal (2013).