I had some acne as a teen, and here is what I learned:
(1) Take vitamin A supplements and eat plenty of foods rich in vitamin A and beta carotene such as carrots and cantaloupe. Start with 25,000 IU daily. Vitamin A is the #1 nutrient for your skin, and it will drastically improve your complexion. However, it does gradually build up in the body over time, so gradually taper-off the dosage to 5000 IU daily.
(2) Vitamin E will reduce scarring caused by acne and help get rid of old scars.
(3) Take 15 - 30 mg of zinc daily with a meal. It kills acne bacteria.
(4) Sunlight clears acne.
(5) Drink a lot of water instead of colas.
(6) Excess salt in the diet causes acne. So, cut way down on salt.
(7) Avoid white, refined sugar products.
(8) Don't put any gunk on your face. It just clogs pores and makes acne worse.
(9) Keep your face clean. Splash it with water regularly.
(10) Eat a healthy diet, avoid fast food, and do cardio exercise.