Sana Khan discusses the skin benefits of taking vitamin C, including dietary consumption and its use in topical formulations
In recent years, the media has turned their attention to the use of vitamin C cosmeceuticals. Many hold the belief that if you follow a sensible skin regimen with a good vitamin C serum, there should be no need for oral supplements or particular attention to vitamin C intake via the diet. While there is no replacement for a healthy diet, the reality is that the stresses and strains of a fast-paced modern life take their toll on the physical and mental faculties of us all; therefore, taking the right supplements can assist you in your quest for a healthy balance. When added to your daily skincare routine, well-formulated products containing vitamin C provide a myriad of health benefits, from helping to even out your skin tone, protecting skin from the visible signs of extrinsic and intrinsic aging, improving hydration, and keeping your skin looking younger for longer.
Vitamin C: what is it and why do we need it?
Vitamin C (ascorbic acid) is an essential nutrient in the body, but sadly most people are unaware of all its benefits. Back in late 2014, news headlines suggested that the Victorian-era disease, Scurvy, was making a comeback, suggesting that we may all require daily supplementation of vitamin C throughout the year. So here are some of the facts to help you make an informed decision about vitamin C applications, whether oral or topical, and whether you actually need them.
Most people are familiar with vitamin C because of its vital support in strengthening immune function or its ability to facilitate the absorption of iron. While vitamin C, a water-soluble nutrient, is an essential part of skin health as a potent antioxidant, it is also crucially required for collagen synthesis. Moreover, vitamin C assists photoprotection from environmental toxins and pollution, repairs photodamage from ultraviolet rays (UV), and promotes wound healing. Publications over the years have shown that application of both dietary and topical ascorbic acid are beneficial in preventing and treating photodamage.
Dietary vitamin C
A plant-based diet consisting of fruits and vegetables provides the best sources of vitamin C given optimal digestion and absorption. Citrus fruits, red and green pepper, kiwifruit, and tomatoes are good examples of dietary sources of vitamin C, while some other foods are even fortified with vitamin C; unfortunately, the latter are often processed and refined. Additionally, the vitamin C content of food may be reduced by prolonged storage and by several cooking methods. Steaming or microwaving may lessen cooking losses. Fortunately, many of the best food sources of vitamin C, such as fruits and vegetables, are typically eaten raw. The recommended dietary intake guidelines for men is 90 mg and 75 mg a day for women.
Is it good for us?
In the quest to increase dietary vitamin C levels, there is no doubt that eating a predominantly plant-based diet, whole grain carbohydrates, and healthy fats is the way to go, which by default avoids sugary and processed foods. These foods do of course happen to be nutrient dense, which in turn facilitates digestion, absorption, and utilization of vitamin C and other co-factor nutrients. Compromised digestion and absorption can have many repercussions on the body, initially on immune function but also the rate of repair and healing process and formation of new collagen as well as mental agility. The plant-based diet also tends to discourage unhealthy weight gain because they tend to be lower in the sugar, saturated fats and man-made chemicals that are often the protagonists of weight gain.
However, there is little dispute that supplementing vitamin C is beneficial for us, and this is when the ‘collagen and vitamin C based supplements’ can become a little misleading. These supplements aren’t just good for us because they are rich in marine collagen and vitamin C — they also happen to be rich in many essential nutrients, antioxidants, and minerals, which benefit the body in many ways other than just anti-aging purposes, such as zinc, which has also been shown to promote healing.
Vitamin C and the skin
Vitamin C resides in large quantities in both the dermis and epidermis of the skin. Intrinsic and extrinsic aging reduces the vitamin C content in the skin, which makes the body vulnerable to UV rays and other pollutants that further exacerbate the decline of vitamin C content, primarily in the epidermis. UV exposure has also shown to cause melanogenesis, resulting in an unevenly pigmented skin tone that tends to increase with age. This suggests two things: that additional vitamin C administration will not only protect the skin from UV-induced photodamage, but it will also repair the skin by increasing collagen synthesis, therefore reversing UV-induced photodamage.
Photoprotection
UV rays decrease vitamin C content in the skin, and this directly correlates to the intensity and duration of UV exposure. When the skin is exposed to UV rays, ROS (reactive oxygen species), such as the superoxide ion, peroxide, and singlet oxygen are formed. These radicals prompt a series of reactions that damage cellular DNA, the cell membrane and the cellular proteins, including collagen. ROS also causes the growth of elastin in dermal fibroblasts, which explains the loss of elasticity observed in photoaged skin. Therefore, by increasing vitamin C administration (topical or oral), you can limit the damage induced by free radicals (donating electrons to the ROS) and, therefore, reduce inflammation and photoaging.
It is important to note that vitamin C is equally effective against both UVB and UVA rays. UVA breaks down collagen, elastin, proteoglycans and other cellular structures in the dermis, whereas UVB causes sunburn, ROS, cellular mutations, and skin cancer. Furthermore, sunscreens only block 55% of the free radicals produced by UV rays. A decline in collagen synthesis creates a disruption in the connective tissue and impairs blood vessels while hindering the process of wound healing. Hence, to fully optimize UV protection, it is important to apply sunscreens as well as vitamin C (topical or oral) to ensure an all-rounded UV-protective effect by neutralizing free radicals too.
Vitamin C: an anti-inflammatory nutrient
Vitamin C inhibits NFkB (nuclear factor kappa light chain enhancer of activated B cells), which is responsible for the production of a number of pro-inflammatory cytokines; therefore, vitamin C has been shown to be a potent anti-inflammatory compound and helpful for other age-related inflammatory skin conditions, such as rosacea.
Collagen synthesis
Oxidative stress and damage to skin cells in both extrinsic and intrinsic aging results in changes to the skin’s structure. In addition to its antioxidant function, vitamin C regulates the synthesis of the structural protein collagen. Specifically, vitamin C has been shown to modulate collagen mRNA, thus regulating and increasing collagen protein synthesis to repair damaged skin. As this happens, elastin production decreases simultaneously (elastin is often overproduced in response to photodamage).
The right dose of vitamin C
Many people nowadays do not eat enough plant-based food to consume the vitamin C they require, and, if they do, many often compromise digestion and absorption resulting in a gradually increasing vitamin C deficit. Although still uncommon, recent figures indicate that vitamin C deficiency is becoming more prevalent. This is also partly due to the exposure to man-made chemicals and environmental pollutants, such as smoking, which promote extrinsic photoaging. There are also people in risk groups who could be more prone to deficiency, such as those who suffer from digestive conditions or take medication that compromises digestion/absorption.
Supplements
Oral supplementation has shown to effectively increase vitamin C levels in the skin. However, when plasma vitamin C levels are saturated, skin vitamin C levels do not rise further. Most multivitamins have a generous amount of vitamin C, but it is also available in the market as a sole supplement. Recently, it has been found as a potent ingredient in many ‘collagen’ or beauty drinks and, therefore, recommended by a large number of aesthetic practitioners. Although vitamin C is water soluble, caution is advised as excessive intake of this supplement can cause toxicity in extreme cases.
The vitamin C in dietary supplements are usually found in the form of ascorbic acid, but some supplements have other forms, such as sodium and calcium ascorbate. There is no study to date to suggest that any one form is better. L-ascorbic acid is the active synthetic form of vitamin C, and its absorption is limited in the gut; therefore, only a certain amount of supplement will be absorbed no matter how high the dosage. This is why some practitioners prefer the use of topical administration over oral, which will be discussed in further detail below.
Topical application of Vitamin C
Topical administration of vitamin C has been on the rise lately. In recent studies, it has been found to reduce the number of sunburned cells and UV induced photodamage. The stratum corneum can prevent maximum topical absorption of vitamin C. Research continues to demonstrate that the removal of the stratum corneum by laser, chemical, or mechanical procedures can further improve absorption.
The stability of vitamin C in topical solutions is a concern, as exposures to air, heat, and light may gradually degrade vitamin C. Although ascorbic acid is the most effective form for topical administration, it is the least stable in solution. However, stable synthetic forms, such as ascorbate phosphate, are considered to have limited absorbency. Ascorbyl palmitate, another stable form also has limited absorption, and some publications indicate the presence of toxic effects with ascorbyl palmitate usage. Magnesium ascorbyl phosphate is the most stable and preferred as it is easily absorbed into the skin and has a further hydrating effect on the skin by decreasing dermal water loss.
The stability and utilisation of topical vitamin C may be increased with the addition of other antioxidant compounds, such as glutathione, ferulic acid or vitamin E to improve skin health. Furthermore, some studies suggest that topical application of vitamin C alone or in combination with other compounds may result in greater photoprotection than oral supplementation because of the more direct route of administration. Topical application appears to be an effective route for delivering ascorbic acid to the skin because ascorbic acid appears to be taken up readily at an acidic PH level. Despite the inconsistencies in vitamin C preparations regarding stability, recent publications suggest that topical vitamin C preparations are most effective in protecting against UV induced photodamage as well as having the ability to treat the skin damage and wrinkling.
Reactions of topical vitamin C
Topical vitamin C is essentially safe to use on a daily basis for prolonged durations. It can be used safely in conjunction with other common topical anti-aging agents, such as sunblocks and topical vitamin A. Minor adverse reactions include a brown staining of the skin and hair, which is caused by oxidative changes to the vitamin C. The toxic doses of vitamin C that lead to cellular damage are over one hundred times higher than the daily recommended dose, making it rare to reach toxicity.
Intravenous vitamin C
Intravenous (IV) infusions are another recent trend that allows vitamin C to reach much higher levels in the blood than when taken by mouth or administered topically. Often, vitamin C infusions are delivered in a cocktail of nutrients, such as glutathione for ‘skin-lightening effects’ in many Asian countries. However, vitamin C IV infusions have been used in cancer treatment protocols and are administered to patients to prevent infections, fatigue and cancer growth. The contraindications for intravenous vitamin C supplementation are glucose-6-phosphate dehydrogenase deficiency and chronic renal failure, although some publications suggest that IV infusions have not been in use long enough to accurately measure safety and efficacy in the long run.
Summary
Vitamin C is naturally occurring with multiple desirable holistic effects. For aesthetic and anti-aging purposes, the benefits include a minimal risk of toxicity, improvement in photodamage, reduction in tissue inflammation and promotion of tissue healing. Continuing research has been geared towards improving ascorbic acid delivery into the dermis for stimulating collagen production and scavenging free radicals. Vitamin C holds potential as a mainstream remedy in future anti-aging and aesthetic treatments.
Oral supplementation with vitamin C may help prevent UV-induced photodamage, especially in combination with nutrients, such as zinc, vitamin A and vitamin E; however, the extent of the protective effects will require further research. Overall, limited data suggests that vitamin C consumption alone provides insufficient antioxidant protection against UV radiation. However, multiple studies have found that oral supplementation with a combination of vitamin C and vitamin E are effective in reducing and treating photodamage. Dietary intake of vitamin C is most likely inadequate alone to protect the skin from extrinsic and intrinsic aging. For desirable, long lasting, and optimal results, patients should be advised to consider oral supplementation while eating a range of nutrient rich foods preferably in raw form; so perhaps smoothies and juices aiming to support digestion, absorption, and utilization of vitamin C and co-factors. But it is equally important to consider using vitamin C serums combined with other ingredients, such as glutathione and vitamin E topically, and perhaps to encourage the use of treatments to remove the stratum corneum to further enhance the topical absorption of the serum in the skin.
Disclaimer: Specific supplements are used for a range of reasons, and a one-size-fits-all approach shouldn’t be adopted. Also, pregnant/lactating women and anyone on medication should always consult a doctor before embarking on a supplements programme.
