Bright Moms: Everything You Want to Know About Vitamin C

The other day, a patient asked me about vitamin C. She is in her early 50s, with light brown hair and blue eyes and is fair-skinned. She grew up in Georgia and her skin has a lot of sun damage (freckles, uneven skin tone, fine lines). She wondered if a vitamin C skincare product might help her achieve clearer, brighter skin.

While our true Bright Girls don't necessarily need vitamin C products for their perfect skin, we moms grew up in a generation where our skin sustained a decent amount of sun damage (I'll speak for myself!) I am a fan of vitamin C for the skin: this is a proven and well-established antioxidant that acts as an extra layer of protection for our skin and helps neutralize inflammation. Vitamin C is often a foundational product in adult skincare regimens. 

I am not, however, a big fan of vitamin C products for teen skin and tween skin. As the mom of 3 teens/tweens myself, and after decades in Dermatology practice, I have seen firsthand how strong skincare products, such as many vitamin C formulations, can actually irritate and inflame young skin, harming the skin barrier, and causing more harm than good.

For those of you who are wondering about vitamin C skincare (for yourselves or maybe asking for a friend), below are some key takeaways.

Why is Vitamin C serum so popular?

• Vitamin C is a topical antioxidant, and works in tandem with sunscreen to protect skin cells from oxidative stress. Additionally, vitamin C helps fend off the UVA-induced reactive oxygen species that contribute to photo-aging and breakdown of collagen and elastic fibers.
• Topically applied Vit C enhances the mRNA levels of collagen I and III, promoting collagen synthesis, and allowing the skin to become stronger and more supple. 
• Vitamin C also increases epidermal turnover, helping the skin shed dull, dry skin cells and appear brighter. 
• Vitamin C has been shown to protect skin against UV-damage, but not enough to be substituted for sunscreen. 
• Vitamin C has anti-inflammatory effects in the skin  

What other skincare products should you use with a vitamin C serum?

• When using vitamin C, it's very important to have the right supporting skincare regimen steps (i.e. gentle cleanser, effective moisturizer, and broad-spectrum sunscreen) to minimize any irritation that might come with starting a vit C serum. 
• Vitamin C is an active, so you want to apply this to dry skin, before any moisturizers or oils which can act as a barrier to the penetration of the active ingredients.
• Consumers won't notice much difference after a few weeks of applying vitamin C, but the cumulative benefits over time, with consistent use, can be tremendous. 
• I always advise my patients to apply vitamin C serum as part of their morning skincare regimen due to the UV-protective effective of vit C (i.e. synergistic UV-protection when  layered under your sunscreen), and the antioxidant benefits of vitamin C. However, UV light exposure does lower tissue vit C levels. Essentially, I think of vitamin C as an important step in outfitting your skin to face the day ahead. Vit C prepares the skin to cope with all of the pollution, inflammation, UV damage, etc that it encounters throughout the day, and offers that extra layer of protection from environmental irritants.  

Why are some vitamin C serums are more expensive than others? Does more expensive mean better?

• Several factors, including: the concentration of active vitamin C, the pH of the serum, the thickness and viscosity of the serum or cream, packaging, and additional ingredients can all impact the efficacy of a vitamin C serum as well as the cost.
• Vitamin C becomes unstable when dissolved in water; so combining vitamin C with complementary ingredients such as vitamin E, hyaluronic acid, ferulic acid, and glutathione help stabilize the vitamin C, thereby maintaining its potency and efficacy. 
• The concentration of vitamin C can impact the price. Consumers should look for vitamin C concentrations between 10-20%; concentrations beyond 20% really don't offer any significant additional benefit and can be more irritating to the skin. Individuals with dry or sensitive skin should start with a lower concentration (10%) vitamin C serum while those with more robust skin can handle the 20%. When recommending a vitamin C product to patients, I take into account their skin type, skincare goals, and other products in their regimens so we can select the vitamin C serum that will work optimally for them.
• Packaging can be a significant factor in cost. Although the branding and the box in which your bottle of vitamin C arrives have no impact on the efficacy of your vitamin C serum, the bottle or tube that holds the vitamin C does. Vitamin C can oxidize more rapidly when exposed to air and light, so an airtight container that is opaque or composed of dark glass is best. Vitamin C serums that are stored in the dark undergo oxidative degradation at a much slower rate compared to serums that are stored in light.
• Vehicle ingredients are the additional ingredients in a formulation that facilitate the penetration of the vitamin C. Vehicles are very important as they help determine how well and how far the vitamin C molecules can travel into the skin. Depending on the efficacy and cost of these, the price of a vitamin C serum can scale accordingly.
• Vitamin C, also known as ascorbic acid, performs best when maintained in an acidic pH of around 3. Maintaining a lower pH slows down the rate of oxidation of vitamin C.

What should consumers look out for when choosing a vitamin C product? Powders vs serums?

• Look for a Vitamin C concentration between 10-20% (see above section)
• Solid vitamin C, such as what is found in a powder form, may be more stable than vitamin C in an aqueous solution. When vitamin C is dissolved in water, it decomposes fairly rapidly; this is why stabilizing agents, such as ferulic acid, vitamin E, and hyaluronic acid are often mixed with vitamin C to obtain a synergistic and stabilizing benefit. 
• I advise my patients to stick with a dedicated vitamin C serum as there are too many variables that can affect the potency and efficacy of a powdered vitamin C product that is applied to the skin. The pH of your other skincare products, whether or not you have water or toner on your skin, and the amount of powder that you apply can all affect how the vitamin C powder performs. Rather than "guessing" by mixing and matching homemade concoctions, I prefer to recommend products that have clinical studies to support their efficacy.

Bright Moms: I hope that this article has been an informative resource for you. Please reach out with any additional questions I can answer!

Angela Casey MD, Double board-certified Dermatologist and Dermatologic Surgeon