Vitamin glow generally refers to the radiant and healthy appearance of skin that is achieved through the use of vitamins, particularly Vitamin C.
Vitamin Glow C products, like serums, often aim to provide antioxidant support, improve signs of sun damage, and brighten skin tone for a "glow-from-within" complexion. They typically contain a high percentage of naturally derived ingredients and are suitable for dull and all skin types.
Essentially, "vitamin glow" describes the desired outcome of using vitamin-infused skincare: brighter, healthier, and more radiant skin.