Vitamin A (retinol, retinoic acid or Retin-A, retinyl propionate, and retinaldehyde): In its various forms, vitamin A increases elastin, collagen, and the natural moisturizer hyaluronic acid in the skin. It's the only thing you can apply to repair sun damage, giving you a smoother, less wrinkled complexion.
Vitamin C: Also stimulates collagen and elastin growth and helps thwart free radicals. (Vitamin C rapidly breaks down when exposed to light and oxygen, so the jar should be opaque and kept sealed.)
Vitamin E: An antioxidant, vitamin E acts to slow wrinkle production. Some research suggests it may also help protect against skin cancer. (Must be in the form of DL-alpha-tocopherol to make a difference, so read the ingredients on the label.)