I wish this whole area was less confusing to consumers!  And, it is confusing!  For your specific question, the answer is easy because tretinoin IS a Vitamin A cousin.  This whole group which are called retinoids (Vitamin A cousins basically)  include tretinoin (the generic version), Renova, Retin A, Retin A micro, Refissa, Differin, retinols, and there are many others.  The choice of which one depends on what you are using it for and how oily or sensitive your skin is.  Dr. I