Introduction

The basics of skin health

The skin, our body’s largest organ, wraps around us, serving as an intricate shield composed of multiple layers of cells. This dynamic barrier is our first line of defence against external threats including pathogens, harmful ultraviolet (UV) radiation from the sun, and environmental stressors. A great way to fortify this shield is by having a skincare routine, but also with a well-balanced diet, rich in nutrients that will keep our skin cells healthy and resilient.

While numerous nutrients contribute to optimal skin function, certain vitamins stand out as superstars, offering multiple benefits for skin health. This article explores the significance of vitamins A, C, E, D, and K, delving into how they contribute to skin wellbeing and the foods that can help raise their levels.

Difference between fat-soluble and water-soluble vitamins

Vitamins can be fat-soluble, like vitamins A, D, E, and K, which dissolve in fats and are stored in our body’s fatty tissues and liver for an extended period. Thus, excess intake of these vitamins may lead to toxicity.¹ In contrast, other vitamins are water-soluble, like vitamins B and C, which dissolve in water and are easily excreted in urine. For this reason, they need to be regularly replenished as they have limited storage in the body.²

Having sufficient vitamin levels is essential for our skin health

Having sufficient levels of these vitamins is essential to preserve healthy skin. However, the World Health Organisation estimates that 2 billion people live with vitamin deficiencies worldwide.³ Unhealthy skin can manifest through various symptoms, sometimes indicating underlying issues. Below are common symptoms of unhealthy skin:

• Dryness and flakiness
• Redness and inflammation
• Swelling or puffiness
• Breakouts and acne
• Wrinkles and fine lines
• Dark spots and hyperpigmentation

But how do these vitamins tackle these symptoms promoting skin health?

The role of vitamins in skin health

Vitamin A: The radiant regenerator

Vitamin A is a collective term for a group of fat-soluble nutrients that are highly beneficial for our vision, growth, and skin health. These nutrients achieve this by encouraging skin cell turnover, fortifying our skin barrier, and balancing our immune system. Some examples of vitamin A derivatives are retinoids, such as retinol, which is commonly used in anti-ageing and acne products.³

Importantly, vitamin A precursors need to be obtained from our diet, as our bodies cannot make it from scratch. An example of this is foods containing beta-carotene, a pigment that our body can easily convert into vitamin A. Some examples of foods containing vitamin A precursors include oily animal products (e.g. oily fish and egg), and colourful vegetables like sweet potatoes and carrots.

By stimulating the proliferation of the skin cells, vitamin A helps shed the outer layer of dead cells in our skin, helping reveal the fresh skin hidden underneath. This helps combat acne while also reducing the appearance of fine lines and wrinkles.³ Interestingly, recent studies have also found that vitamin A may contribute to keeping our immune system balanced and ready to fight bacteria or viruses that may penetrate through the skin.⁴

Vitamin C: The antioxidant superhero

Vitamin C, also known as ascorbic acid, is a potent antioxidant that has a pivotal role in preserving skin health. Like vitamin A, it needs to be obtained through diet, but because vitamin C is a water-soluble vitamin, it needs to be replenished every day. Vitamin C can be obtained from most cruciferous vegetables and fruits, like citric (e.g. lemons and oranges), berries and tomatoes.

Vitamin C can be pictured as a superhero with multiple powers. As an antioxidant, it has an important role in reducing the DNA damage that occurs after oxidative stress, a natural process resulting from activities that add some stress to our cells, such as UV-ray exposure, smoking, environmental pollution, or just from average day-to-day activities. This process can have a negative effect on the health of our cells, accelerating ageing and increasing the risk of cancer.

Luckily for us, vitamin C has a powerful effect counteracting this oxidative natural process, by neutralising the molecules released during the oxidative process, and hence preventing the associated DNA damage. This is great news for our cells, if our DNA is protected, our cells are too, keeping us youthful and healthy for longer.³

• Improving skin texture, collagen and elastin synthesis—Another superpower actively used by vitamin C is its ability to stimulate the synthesis of two very important proteins for the health of our skin. These proteins are collagen and elastin, which improve the texture, strength and elasticity of our skin, traits not only associated with a healthy skin barrier but also a youthful appearance³
• Scientific studies supporting vitamin C role in promoting skin health–Scientific studies consistently demonstrate the health-promoting benefits of ascorbic acid for skin ageing and appearance. Both oral intake and topical application of vitamin C have shown positive effects. For instance, antioxidant supplementation, including vitamin C, led to significant improvements in skin moisture, evenness, and elasticity in individuals with clinical signs of skin ageing over a ninety-day period.⁵ Another study revealed enhanced skin texture, reduced dark spots, and smaller pores in men after oral supplementation with vitamin C⁶

Moreover, direct application of vitamin C on the skin demonstrated positive outcomes. Women exhibiting signs of ageing experienced improved skin hydration, softness, laxity, reduced roughness, and diminished wrinkles after applying a vitamin C lotion on their forearms and neck for six months.7 Vitamin C also exhibited a protective role against sunburn when combined with vitamin E and other plant antioxidant. This combination acted as a shield, enhancing cellular resistance to sun-induced damage, thereby reducing sunburn and potentially lowering the risk of skin cancer.⁸

Vitamin E: The cell membrane guardian

Vitamin E is another fat-soluble vitamin which preserves our skin health by acting as a strong antioxidant, just like vitamin C. Vitamin E is exclusively synthesised by plants, and you can picture it as a good old friend, as it has been used in dermatology for more than 50 years due to its multiple benefits.⁹ You can easily find it in plant oils, like olive and sunflower oil, as well as green leafy vegetables.

Like vitamin C, vitamin E fights the damaging effects of oxidative stress, therefore preventing DNA damage and premature skin ageing. Interestingly, vitamin E is particularly amazing at protecting the membranes of our cells, which are the fatty walls that surround them.

Keeping our cell membranes strong is important, as they act as gatekeepers, regulating the traffic and ensuring only the right substances are allowed in while keeping the cells’ essential components safe. By supporting these gatekeepers, vitamin E strengthens our cells and reduces skin inflammation, helping alleviate skin inflammation, particularly in conditions like acne.³

Vitamin D: The sunshine vitamin

Vitamin D, another fat-soluble nutrient is renowned for its beneficial role in promoting muscle and bone health by encouraging our body to absorb calcium. Different from other vitamins, vitamin D is also known as the ‘sunshine vitamin’, as it is produced by our bodies from cholesterol after being exposed to the sun.³ For this reason, you can naturally increase your levels of vitamin D by exposing yourself to the sun for 10-15 minutes every day, and increase them further by consuming vitamin D-rich foods, like salmon, tuna, and cod liver oil.

Its multiple skin health benefits include balancing our immune system, ensuring its efficiency, decreasing inflammation, reducing DNA damage resulting from UV radiation, and possibly preventing skin cancer, although this requires further research.³ Even though the mechanisms behind its skin-protective role are still not entirely clear, research suggests that having insufficient vitamin D may contribute to developing skin-related inflammatory diseases, like atopic dermatitis, which is a very common skin pathology affecting 1 in 5 children.¹¹

Because it is thought that 40% of Europeans have vitamin D deficiency, it is encouraged to take it also as a supplement, especially during the winter months when sun exposure is limited.¹²

Vitamin K: The dark circle fighter

Vitamin K is another fat-soluble vitamin important for our cardiovascular system, while also assisting in blood clotting and wound healing. Interestingly, we get this vitamin from both plant and animal foods and our intestinal microbiota. The intestinal microbiota is composed of millions of beneficial microorganisms (like bacteria, fungi and viruses) that live in our gut and help us digest food, support our immune system, and prevent disease.³

Vitamin K’s role in promoting skin health comes primarily from its importance in wound healing and promoting depigmentation, therefore helping reduce stretch marks, scars, and dark circles under our eyes. For example, a study found that topical application of vitamin K on skin wounds accelerated healing time in people who had been injured. It is thought that vitamin K achieved this by stimulating the proliferation of skin cells, the production of collagen, and the formation of blood vessels.¹³

Vitamin K deficiencies are very rare, so there is no need to worry about increasing its intake unless specifically advised by your GP. However, if you would like to do so, you can take leafy vegetables like kale, spinach and fermented soybeans.

Summary

A well-balanced diet coupled with proper skincare practices is crucial for maintaining healthy skin. Vitamins A, C, E, D and K act as vitamin superstars, each contributing in different ways to skin wellbeing. Vitamin A increases skin cell turnover and provides immune balance, while vitamins C and E have potent antioxidant effects and enhance skin texture, supporting collagen synthesis, fighting oxidative stress, and strengthening our cell membranes. Vitamin D plays a multifaceted role in immune balance and reducing inflammation, and lastly, vitamin K accelerates wound healing and depigmentation. However, while these vitamins offer benefits, they are not a cure-all, and each person might have different needs. It’s advisable to consult with a healthcare professional or dermatologist for personalised advice, especially if you have specific skin conditions or are thinking of vitamin supplementation.