I'm not sure about vitamins but I know that drinking alot of water helps a bit. It hydrates your skin and helps rinse away some of the bacteria. Sunlight and vitamin A (i think) are also a great natural way to avoid acne.

I would try to find the most natural cleanser you can... Aveeno is usually pretty good and gentle,... my sister sells all natural skin care products from a company called "daisy blue naturals"

http://4017.daisybluenaturals.com/MyStory.aspx ... this is the site - the facial cleansers sill be under products...and then facial...and then u can choose oily/dry/or sensitive hope this helps