Vitamin C (L-ascorbic acid) For Skin
Vitamin C has many benefits as a cosmetic & general health ingredient. The following are important facts about the vitamin.
- It is a popular antioxidant with many benefits
- Cannot be synthesised in vivo by humans but most plants and animals can.
- Its deficiency can lead to scurvy; a condition that presents with bleeding gums.
- It is associated with a reduced risk of certain cancers, cardiovascular disease, cataracts and it improves wound healing
Topical Benefits of Vitamin C – L-ascorbic acid
It is naturally unstable but more stable forms at pH of <3.5 have been formulated for topical use. At this pH, ionic charge is removed and its molecule is easily transported across the stratum corneum (outermost layer of the skin forming your Skin Barrier).
Benefits as an anti-oxidant
- Free radical damage: exposure to UV light promotes generation of reactive oxygen species (ROS). These include superoxide, peroxide and singlet oxygen. Vitamin C donates free electron to the ROS therefore neutralising the free radicals reducing the processes eventually lead tocollagen breakdown. Oxidised forms of Vitamin C can be converted back to Vitamin C by the enzyme de-hydro-ascorbic acid reductase in thepresence of glutathione. This is a special property of Vitamin C as an antioxidant because it can continue offering free radical scavenging effects for long.
- Vitamin C is hydrophilic and Vitamin E is lipophilic. Synergistically, they protect the respective cellular compartments by reducing premature cell apoptosis and thymine dimer formation (DNA Damage) giving up to four times more protection than when Vitamin C is used alone. Vitamin E can spare electrons to used up vitamin C molecules to make them active again. There is notable protection against UVB rays effects when the two vitamins are used in combination. UVB rays usually damage the skin and increase risk of premature skin aging and cancer.
- Addition of ferulic acid increases the efficacy of Vitamin C by up to eight times. The commonly used formula is 15% Vitamin C, 1% Vitamin E and 0.5% Ferulic. Other useful substances in increasing bioavailability include zinc and tyrosine.
- Prevents sun damage and improves sun protection when combined with sunscreen. It is equally effective against UVA (230mm-400mm) and UVB (290mm 320mm)
Benefits of Vitamin C in Collagen Synthesis.
- It serves as a cofactor for the enzymes prolysysl & lysyl hydroxyls which are responsible for cross-lining stabilising collagen molecules.
- It stimulates collagen gene expression
- It directly activates transcription of collagen synthesis and stabilises pro-collagen mRNA molecules
- Therefore, it significantly improves wrinkles and hydration
Benefits as a skin brightening and lightening agent
It is a non-toxic interrupter of melanogenesis
- Reduces tyrosinase kinase activity regulates controls melanin production
- Decreases peri-follicular pigmentation
Benefits of vitamin C as an anti-inflammatory
- It inhibits NFkb (nuclear transcription factor kappa B) that is responsible for the activation of cytokines such as TNF-alpha, IL1, 6 and that induce inflammation.
- It can be used for acne vulgaris, rosacea and wound healing and also in post-operative erythema that some patients may develop following laser therapy.
- It helps to prevent post inflammatory hyperpigmentation (PIH) skin disorder due to high amounts of oxidative stress produce in response to injury.
Side Effects of topical Vitamin C
The safety of Vitamin C is an established fact. Its therapeutic index is very high. You need to take between 100 and 200 times its recommended dose for toxic effects to show. However, some user may develop the following problems that in most cases are self-limiting.
- Stinging, dryness and erythema but these can be treated easily with a moisturiser
- Once applied cannot be washed off
- Rarely, urticaria and erythema multiform have been reported