The Benefits of a Vitamin C Serum Vitamin C is essential for many cellular and skin functions, including collagen synthesis, maintaining skin strength and integrity, wound healing and free radical and UV protection, according to Dr. Magovern. “Vitamin C is a potent antioxidant that is naturally and normally found in the skin in high concentrations,” she explains. “As an antioxidant, it neutralizes free radicals in the skin. Free radicals, which are formed from things like the sun, pollution, stress and smoking, damage the DNA of the cell, which can lead to premature aging and skin cancer. Vitamin C also boosts collagen production and reverses cell damage, which helps keep the skin firmer and even helps fade and prevent brown spots and pigmentation.”