When I was a teenager -- around 1982 -- my physician prescribed vitamin A 100,000 u/day. High dose vitamin A was used prior to the launch of Accutane. Vitamin A didn't help me at all. Fifteen years later I took Accutane and it cleared my skin completely.
My physician checked my liver enzymes monthly while I was on high dose Vitamin A and warned me not to get pregnant. Same deal as Accutane, except my skin was still a mess.
Pantothenic acid and vitamin D help my skin the most, along with moderate doses of zinc, vitamin A, progesterone cream, and saw palmetto (if your Acne is hormonally related).