Hi, I'm a scientist, but unfortunately, I'm a geneticist, not a veterinarian
. But I LOVE scientific discussions!!!
I think that the reasoning behind vitamin C supplementation for ear raising is that vitamin C aids in cartilage formation (cartilage is what holds the ears upright). That said, I don't know if there are any studies that show that vitamin C helps ears raise, and my understanding is that in normal, healthy dogs, vitamin C supplementation is not necessary (because dogs produce their own vitamin C) and
could have adverse consequences. Here's another article on vitamin supplements for dogs from webmd that was produced in consultation with veterinarians:
Dog Vitamins and Supplements: Nutrition, Joint Health, and More
I agree with the poster who said that if you are going to try to supplement your puppy's vitamins, look to natural sources. Just be sure that the natural source is something that is not toxic to dogs, because certain foods that humans eat (like chocolate and onions) ARE toxic to dogs.