Vitamins affect the skin. Healthy skin requires a variety of vitamins to keep it resilient; specifically, vitamins A, Vitamin B3, vitamin C, vitamin D, and vitamin E. Lack of vitamins can lead to dull lifeless skin.
Vitamin A (Vitamin A derivatives, Retinol palmitate, retinoids)
Vitamin A increases blood flow, stimulates the skin and protects against sunburn and is supposed to heal damaged connective-tissue, which helps to smooth the appearance of wrinkles and scarring.
Synthetic vitamin A-like compounds called retinoids. Natural compounds can be used e.g. those found in Carotene.