Vitamin C, also known as ascorbic acid, is a vitamin that most animals can make. Humans, primates, birds, and guinea pigs are the exception and must get it through diet. Vitamin C is found in most tissues in the body where it is involved in the synthesis of collagen. Collagen is the most abundant protein in the body and one that's involved in holding connective tissue together. It's found in great abundance in cartilage, ligaments, tendons, bones and skin.
Vitamin C is also involved in producing hormones and neurotransmitters that direct bodily functions and enhance the immune system, the body's defense system against disease. In addition, vitamin C is an antioxidant vitamin that helps to protect cells against oxidative damage and aids in the absorption of iron. Vitamin C is a vitamin of great functional importance and has many roles in the human body.
Vitamin C deficiency leads to a serious medical condition called scurvy. People with scurvy experience bleeding gums, easy bruising, fatigue, loss or teeth and poor wound healing and children with a deficiency of vitamin C often have growth problems. Fortunately, vitamin C is found in a variety of foods. Those with especially high quantities of vitamin C include citrus fruits, kiwifruit, strawberries, green peppers, broccoli and cauliflower. Some people, including smokers, older people and alcoholics, are a greater risk for vitamin C deficiency and need higher amounts of this vitamin. Stress also appears to increase the requirements for vitamin C. Cooking can destroy some of the vitamin C in foods.
At one time, high levels of vitamin C were believed to protect against the common cold and shorten its duration. More recent research has called this into question. What seems more likely is a deficiency of vitamin C increases the risk for colds and flu since it's important for a healthy immune system. There's also some evidence that a diet rich in vitamin C reduces the risk of heart disease, some types of cancer and cataracts.
Vitamin C has anti-aging benefits when used topically. Because of its antioxidant activity, it has the ability to reduce skin damaging free radicals that form in response to sun exposure and exposure to environmental pollutants. It's now not uncommon to find vitamin C in sun screen products since they provide additional protection against UV damage. Vitamin C also boosts collagen production. Collagen is a protein in the dermis of the skin that gives it its youthful support. Collagen in the skin declines with age, which is one reasons skin sags and becomes wrinkled.
Vitamin C is most effective for boosting collagen production in the skin when applied topically. Unfortunately, some forms of vitamin C aren't able to easily penetrate the epidermis. In addition, vitamin C is unstable and breaks down when it's exposed to light. That's why it's important to keep products that contain vitamin C in an airtight container and not expose them to light. One of the most stable forms of vitamin C, available in some skin anti-aging products, is magnesium ascorbyl phosphate.
Topical vitamin C also helps to lighten pigmented areas. Therefore, it's useful for treating sun spots, and melasma. It also helps to reduce inflammation and redness after laser skin resurfacing and is effective for treating stretch marks.
It's important to get adequate amounts of vitamin C through diet, but using topical products that contain vitamin C provides additional protection against the sun's damaging rays. In addition, it helps to boost collagen production, which can reduce the appearance of fine lines and wrinkles. Topical vitamin C also has exfoliating properties, similar to alpha hydroxy acids and increases shedding of dead skin cells that make skin look dull. Therefore, it improves skin texture when used on a regular basis. It works synergistically with retinols and alpha hydroxy acids.
Topical vitamin C is usually well-tolerated but can cause some irritation in sensitive types. Although it offers some protection against sun damage, it's important to continue to wear a sunscreen when using vitamin C products. Vitamin C in the quantities found in cosmetic and skin care products appears to be safe. It can be found in a variety of products including facial moisturizers, eye creams and anti-aging products.