Vitamin A has long been used for all its benefits.  It is of course an essential vitamin, and you would need to use it to live.  But while vitamin A is an essential vitamin needed to make your diet complete, it is also a powerful antioxidant.  Doing this, it will help you to prevent premature aging in some ways by killing off the free radicals that would otherwise hurt your skin and body as a whole.  In addition, when used on the skin, vitamin A has been known to actually increase the skin cell turnover, eliminating cells that would clog pores while also eliminating rough and dry patches and otherwise problem areas.  This is why it has been used for acne.  But this is also why it has been shown to reduce some fine lines over time.  It simultaneously thickens the epidermis.  A thinning epidermis is often what is actually responsible for the greater susceptibility to aging.  So obviously, you could benefit from using it to a greater degree and see the benefits you want.  Overall, vitamin A can cause quite a few side effects in the forms they have now created.  But in its raw form especially, it generally is just used to help to improve your skin and protect it from future damage in general.