Topical Vitamin C Serum Benefits and Concerns

Vitamin C is an essential nutrient that plays a variety of roles in human health. In particular, it supports collagen synthesis and, as an antioxidant, can help improve your skin. Topical vitamin C for the skin is thought to help prevent aging, pigmentation and sun damage, but hasn't been studied as much as other forms of this essential nutrient.

Read more: 43 Supplements Exposed: Which Ones to Consider, Which Ones to Avoid

Vitamin C, also known as ascorbic acid, has various roles in the body. This essential nutrient can:

• Help the body make collagen
• Help the body absorb the iron found in plant-based foods
• Improve fertility
• Improve skin health
• Minimize the effects of aging, particularly wrinkles
• Protect the body's cells from free radicals, which helps prevent disease
• Protect the skin from damage by ultraviolet light exposure by acting as an antioxidant
• Support the function of the immune system
• Support wound healing

You can find vitamin C in a variety of foods, especially fruits and vegetables, including peppers, broccoli, kiwi fruit, citrus fruits, strawberries and Brussels sprouts. According to the National Institutes of Health, most women should consume about 75 milligrams of vitamin C per day, while most men should consume about 90 milligrams per day.

Vitamin C is also available as a supplement that comes in topical, oral and injectable forms. These supplements may be made from products like synthetic ascorbic acid or a type of mineral ascorbate, also known as buffered vitamin C.

The effects of all types of vitamin C are generally considered to be equivalent, but some may be preferred over others based on the reason the supplements are taken. Regardless of the source it comes from, vitamin C is most effective when combined with other micronutrients like vitamin E or zinc.

Read more: 11 Nutrients Americans Aren't Getting Enough Of

The vitamin C in your body is largely stored in your skin ⁠— specifically in your epidermis and dermis. However, as you get older, the amount of vitamin C in your skin decreases gradually. Exposure to excessive amounts of UV light, cigarette smoke and other pollutants can also reduce the amount of vitamin C in your skin.

To counteract this, people often take extra amounts of this nutrient, beyond the regular daily requirements. For example, the National Institutes of Health recommends that people who smoke take an additional 35 milligrams of vitamin C per day.

When you take oral vitamin C supplements, these pills are digested and the nutrient travels to your skin. Because of this, some people choose to use topical versions ⁠— topical vitamin C serum effectiveness can be equivalent to that of oral vitamin C.

However, most people who choose to take the vitamin in this form are looking for some type of cosmeceutical benefit.

According to the Linus Pauling Institute and a July 2017 study in the Journal of Clinical and Aesthetic Dermatology, vitamin C serum benefits include:

• Helping replenish vitamin E, which also works as an antioxidant
• Neutralizing the negative effects of UV radiation and pollution, thanks to its role as an antioxidant
• Preventing dry skin
• Protecting against the effects of UV-related aging, like spider veins, coarse skin and wrinkles
• Protecting against UV-induced suppression of the immune system
• Protecting against UV-related cancers
• Promoting the synthesis of collagen
• Supporting wound healing, particularly of burns or pressure ulcers

Topical vitamin C can also help decrease melanin formation, making it a much safer and healthier antipigmentation agent than commercial serums and creams that are used to lighten skin.

Read more: 10 Recipes for Glowing, Healthy Skin

Vitamin C serum's uses can be similar to oral supplements, but only when the product has been prepared correctly. In many cases, the ideal product has to have a pH of less than 3.5 (meaning that it is fairly acidic) or it won't be absorbed by the skin. There are products with higher pH levels sold, but these products may contain additional ingredients that prevent vitamin C from being absorbed by the skin.

Vitamin C serums also need to be prepared at very specific concentrations, and the best products are prepared with a concentration of the vitamin that ranges between 10 and 20 percent. Topical products are different from oral supplements; they need to be stronger than 8 percent, but no more than around 20 percent.

Products weaker than 8 percent won't be effective, while products that are much stronger than 20 percent are considered to be too high. In the best case scenario, such products can be less effective, but when prepared at high concentrations, they also have the potential to cause side effects.

When used at doses that are too high, vitamin C serum side effects are minimal, typically causing skin irritation. If you find that your topical vitamin C is causing rashes or similar issues, make sure you're not using a product with a vitamin C concentration that's above 20 percent.

If you're still experiencing side effects from your vitamin C serum, you may want to switch to a weaker serum ⁠— products as high as 10 percent in concentration have not shown any side effects.

The main concern when you choose a topical vitamin C product is that it is likely to degrade. This nutrient is known to degrade when exposed to heat (for example, when vitamin C-rich foods are cooked).

The effect, unfortunately, applies to topical products as well; vitamin C can degrade in heat, air and light. This means these products can lose potency quite quickly and may become ineffective unless stored and used carefully.

Finally, it's quite easy to slather on topical vitamin C serums. However, you should remember that it's possible to consume too much of this nutrient. When taking vitamin C supplements of any type, make sure your daily total doesn't pass 2,000 milligrams.

If you take too much vitamin C, it can actually reduce the levels of other nutrients in your body and cause unpleasant gastrointestinal side effects.