Vitamin E can work wonders on both young and old dogs. Information regarding dosage can be difficult to find, but her is what I have compiled regarding vitamin E and dogs.
Science Diet's newest food, Advanced Protection, advertises that it can make your pet feel and look healthier- but Advanced Protections number one ingredient is still a cheap corn filler that is not healthy for your dog. So what's different?- antioxidents. But you don't have to buy a lower quality food (Than, say, Solid Gold, or Chicken Soup for the Dog's Soul, Eagle Pack, or Diamond) to give your dog the extra antioxidents that he needs.
How Much Vitamin E is Safe?
According to one site on vitamine E and dogs, anywhere from 2.6 to 3 IU per day is appropriate. This would mean a 25 pound dog could receive 75 IU per day, a 50lb dog 150 IU per day, etc. But the average serving of Science Diet Advanced Protection contains 700IU of vitamin E, indicating that for the kind of results their food is producing, a much higher dose would be appropriate.
I currently supplement my Airedale 400 IU per day. Annie was emaciatedly thin when she came home with me as a rescue dog and within 6 weeks had gained 12 pounds. After about 2 weeks on Vitamin E supplements Annie began to blow her coat (Airedales do not typically shed or blow their coats) and a healthy, darker, curlier coat was completely grown in by her next grooming.
Other Vitamins
I also supplement my dog with liquid Chlorophyll. For humans, Chlorophyl is being lauded as a completely safe alternative to aluminum based deodorant. For dogs, Chlorophyll is the active in ingredient in the breath deodorizing treat, Greenies. Liquid Chlorophyll may help improve immune response, but it's best feature is that it deodorizes a dog (and his "droppings") in a completely natual way.