Updated: Feb 9
The question when it comes to vitamin C in a product is how active the compound actually is and the concentration of it to really have an effect on the skin. Read more...
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What is Vitamin C?
Vitamin C is also known as L-ascorbic acid. Vitamin C is an essential nutrient that is found in dietary sources such as citrus, tomatoes, leafy greens, and potatoes. It can also be taken as a supplement. Humans are unable to synthesize it internally and require obtaining Vitamin C from our diets or a supplement.
Why do we need Vitamin C?
The need for vitamin C was determined in the 1930s when the lack of ascorbic acid was linked to a disease called scurvy. Scurvy is a condition that stems from a vitamin C deficiency and manifests itself as a tetrad classically referred to as the 4 H’s:
Perifollicular hemorrhage: bleeding around hair follicles
Bleeding into the periosteum and bones leads to pain
How much Vitamin C is recommended for daily intake?
0 to 6 months
7 to 12 months
According to the Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000.
What about topical Vitamin C?
Topical vitamin C does several things:
It’s a potent antioxidant to prevent damaging our cells from UV and the environment.
It inhibits an enzyme called tyrosinase in the skin to reduce hyperpigmentation from sun damage and melasma.
It is an anti-inflammatory to help with redness in the skin.
It can boost collagen production. Collagen hydroxylase, an enzyme in the skin that is responsible for collagen formation is dependent on Vitamin C to function.
It has been shown to improve the texture and appearance of skin overall.
Promote wound healing.
One note- even though vitamin C can improve pigmentation in the skin, I find the best results are from pigment as a result of sun damage and/or melasma. Its mechanism of improving pigment is by blocking a specific enzyme that triggers hyperpigmentation. Although this can be a similar issue with acne scars, not all pigment is the same and I do not always find that acne scars respond consistently as well to vitamin C compared to other options.
When we ingest vitamin C our body absorbs it but the amount absorbed is limited by how much our gut can actively take in. There is an active transport mechanism for absorption that really limits how much we can actually absorb even at super-high doses. Think of an active transport mechanism as a rate-limiting step- almost like a gatekeeper that can only let in as much as it can keep up with. As a result of this, the impact of ingested vitamin C on the skin with regard to the above-noted activities is minimal compared to topical formulations. That being said, vitamin C in our diet for our skin health is particularly important given the challenges that our skin can face in absorbing topical applications of vitamin C as well.
There are so many versions of Vitamin C topical formulations, how can I navigate my options?
The question when it comes to vitamin C in a product is how active the compound actually is and the concentration of it to really have an effect on the skin. If you are going to look for a vitamin C-containing product, make sure that both the type and concentration of vitamin C are listed.
L ascorbic acid or tetrahexyldecyl ascorbate is the most active type of topical Vitamin C. The concentration should be listed as between 10-20 %.
Vitamin C can be very unstable on exposure to light and essentially be useless once this occurs. It is often sold in opaque or amber-colored glass vials.
Are there any side effects with topical vitamin C?
Very few in the way of side effects are seen with vitamin C so it is safe to try. Irritation, redness, and yellowish discoloration of clothing have been noted.
How should a beginner start incorporating it into their routine?
Vitamin C can be incorporated into the morning and/or evening routine.
When used as a morning product, topical vitamin C can help fight oxidative stress from free radicals during the day with UV exposure.
As an evening product, consider that the damage and free radicals formed through the day from UV exposure and other pollutants can continue to impact our skin hours after exposure. Adding Vitamin C to the evening routine can play a role here.
Can Vitamin C be combined with other products such as Niacinamide?
It is considered safe to use Vitamin C and Niacinamide together in the same product or applied at the same time as a part of your skincare routine.
As we age our skin becomes thinner and more susceptible to redness and inflammation. Niacinamide, also known as vitamin B3, works as an anti-inflammatory to reduce redness and irritation in the skin.
Why do some caution against using Vitamin C with Niacinamide?
There is an old study from almost 60 years ago that showed that when these two products were used together under unique circumstances involving extremely high temperatures led to the development of nicotinic acid that is irritating to the skin. This will not happen in real-world circumstances.
Can these Vitamin C and Niacinamide work together?
There are some studies that show that using these two ingredients together can improve dyspigmentation.
Should Vitamin C be mixed with other ingredients to increase effectiveness -- or does it work best alone?
Many worthy topical vitamin C-containing serums will often be combined with ferulic acid and vitamin E. This is because the combination can actually increase the effectiveness of vitamin C eightfold.
Are there any ingredients to avoid with Topical Vitamin C?
Benzoyl peroxide can potentially deactivate Vitamin C if used together.
And, remember, most vitamin C serums come in opaque or amber-colored bottles to stabilize the product and avoid exposure to light.
Vitamin C Formulations to consider
Skinceuticals CE Ferulic with 15% ascorbic acid combines vitamin C with vitamin E and ferulic acid. This combination makes Vitamin C more potent.
With 10% L Ascorbic Acid, an effective concentration of vitamin C makes this a product to consider adding to your routine. CeraVe is known for its ceramides that help protect the skin’s function.
The La Roche Posay Vitamin C serum has a 10% concentration of Vitamin C. With the addition of Salicylic Acid, the exfoliative benefit of fading excess pigmentation can achieve results sooner.