Vitamins as cosmetic ingredients: the impact on the skin (microbiome)

Vitamins are essential ingredients found in many skincare products. These chemical compounds have been shown to exert a range of beneficial effects on our skin, including its microbiome, to treat a number of dermatological conditions and help maintain healthy skin. Vitamins are essential ingredients in skincare products and have been shown to influence our skin microbiome to help maintain healthy skin.

Below, Hannah English breaks down the key benefits – and the science behind these – for three common vitamins: A, B and C

Vitamin A

Vitamin AVitamin A and related compounds are also known as retinoids. Retinoids are important for several functions in the body (including eyesight!) and are naturally present in healthy skin. Their presence in the skin will decrease with age, oxidative stress, and sun exposure (9).

Retinoids exert most of their anti-aging effects by influencing gene expression, but they do a couple other cool things, too. They penetrate the skin well (7) and remain the gold standard for treatment of skin issues including excessive sebum production, hyperpigmentation, and wrinkles.

Results you can expect from retinoid use include:

  • Prevention of collagen/elastin breakdown (1, 2), meaning skin is full and elastic for longer
  • Enhanced cell turnover and increased collagen production (7), which keeps the skin thick and structured (skin thinning is associated with ageing)
  • Hyaluronic acid presence in skin is indirectly increased! This is a water binding molecule that keeps skin moisturised and bouncy looking (5)
  • Normalised oil production, leading to smoother and less congested skin (7)(8)
  • Retinoids are antioxidants (9), and can even have a protective effect from UVB on human skin (6) (do not replace your sunscreen, but do know it is helpful in this way)
  • Improved appearance of pigmentation, through helping previously damaged cells turn over and normalising the cells’ behaviour, alone or with other ingredients (3)(10)
  • Retinaldehyde has a unique antibacterial effect on unfriendly bacteria acnes and S. aureus (4), making it a great choice to treat mild acne.

Altogether this means reduced fine lines and roughness, and smoother, more even-toned skin. Some of these effects are visible within days while others can take weeks to months.

Vitamin B

Vitamin B

Vitamin B is not a single vitamin but a family of vitamins which are regularly mentioned in skincare conversations.

Niacinamide, or Vitamin B3, is involved in the respiration of every cell. It is also microbiome-friendly with minimal impact on microbial diversity and is readily absorbed into the skin (4). Here’s what it can do:

  • Improve skin barrier function by increasing production of barrier lipids (such as ceramides), and skin barrier proteins as well! This means improved appearance of redness and increased skin hydration, as less water is lost (3)
  • Antimicrobial effects on unfriendly bacteria (7), potentially allowing our skin’s good bacteria to flourish. Indeed, in vitro (cell culture) studies have shown that niacinamide is able to inhibit chemical pathways involved in inflammation caused by acnes bacteria (1) and decreases fungal enzyme activity associated with certain skin infections (10)
  • Antioxidant effects, preventing free radical damage to cells which causes illness and ageing (3)
  • Prevents and fades hyperpigmentation, by inhibiting the transfer of melanin from pigment-producing cells to the nearby skin cells (3)
  • Increases collagen synthesis and cell turnover (3), for smoother skin
  • Inhibits oil production, improving the appearance of pores (5)
  • It’s anti-inflammatory, through inhibition of inflammatory messenger molecules (3)
  • Lastly, there is some evidence that niacinamide exerts a protective effect from UV radiation (6) and can be found in some sunscreens – though it in itself if not an alternative

Clinical studies exist that found changes in the skin at topical concentrations of 2% niacinamide (5), so you don’t need much, although, the skin is very tolerant (3).

Panthenol, or Pro-Vitamin B5, is also very well-tolerated by our skin. It’s great for grabbing water to improve surface hydration and improves barrier function (8) – perfect for use in moisturisers and serums for sensitive skin or post-procedure.

It is also in the beginning stages of research for use with prebiotics for eczema-affected skin (9) – so cool! 

Finally, a word on Biotin, or Vitamin B7. Deficiency is rare, but can cause brittle nails, hair loss, and dermatitis (2). This is why you will find biotin in many over the counter hair, skin and nail supplements.

Vitamin C

Vitamin CVitamin C is essential to our diets and is involved in wound healing. In fact, it was inadvertently the subject of the very first clinical trial – on sailors to treat scurvy!

Vitamin C comes in many forms in skincare and they all have -ascorb- somewhere in their name. It is important to know which form you are using as the effects vary.

Some benefits of the pure form of Vitamin C (L-Ascorbic Acid) include:

  • Vitamin C helps mitigate some of the effects of sun damage, such as by increasing the time taken before burning! (1)(4)(6). This, by no means, means Vitamin C is a sufficient replacement to sunscreen. To understand this, you need to understand that there is more than one way that UV damages the skin…

First, UV radiation harms the skin by directly warping cell DNA

Secondly, UV radiation generates free radicals. Free radicals are molecules that contain an unpaired electron, making them highly unstable and reactive When they are in our bodies, free radicals donate or accept an electron from whatever molecule is nearby – a structural protein, your DNA, the cell membranes etc. This can cause oxidative stress, meaning cells become destabilised and stressed (5). For this reason, antioxidants are beneficial – and Vitamin C is our body’s most powerful and abundant antioxidant

  • Vitamin C can also improve the appearance of hyperpigmentation through tyrosinase (an enzyme involved in oxidation) inhibition and a strong antioxidant effect (6)(7)
  • Vitamin C is required for synthesis of collagen I and III (7), with potential to boost your collagen, thus improving appearance of wrinkles!
  • Vitamin C stimulates barrier lipid/sphingolipid/ceramide production in cell culture, so may even have potential to improve skin barrier function. (2)(3).
  • Vitamin C exerts some antimicrobial effects on aureus, aka Golden Staph (8), and even on C. acnes – the key bacteria linked to acne (9)

To conclude, scientific research has continued to evidence a range of positive effects that vitamins A, B and C have on the skin’s health and, as such, they make good ingredients in skincare products. These vitamins can be found in a variety of cosmetic products, though this isn’t an extensive list and there are many more out there that can be explored!

For more content, read about prebiotics, probiotics and postbiotics as ingredients or browse the Views from section of the Content Hub to hear from our other contributors.


Vitamin A

  1. Fisher et al, 1996
  2. Fisher et al, 1997
  3. Yoshimura et al, 2001
  4. Pechere et al, 2002
  5. Li et al, 2017
  6. Antille et al, 2003
  7. Zasada & Budzisz, 2019
  8. Khalil et al, 2017
  9. Sorg & Saurat, 2014
  10. Ortonne, 2006

Vitamin B

  1. Grange et al, 2009
  2. Almohanna et al, 2019
  3. Berson et al, 2013
  4. Bissett et al, 2007
  5. Draelos, Matsubara & Smiles, 2006
  6. Sivapirabu et al, 2009
  7. Mathapathi et al, 2017
  8. Camargo, Gaspar & Maia Campos, 2011
  9. Stettler et al, 2016
  10. Ciebiada-Adamiec et al, 2009

Vitamin C

  1. Humbert et al, 2003
  2. Uchida et al, 2001
  3. Kim et al, 2015
  4. Murray et al, 2008
  5. Lobo et al, 2010
  6. Al-Niaimi & Chang, 2017
  7. Pullar, Carr & Vissers, 2017
  8. Mousavi, Bereswill & Heimesaat, 2019
  9. Klock et al, 2005

Keep exploring

You have Successfully Subscribed!