It should be noted that several of the traditional approaches that employ vitamin C do so from natural products, like berries, that also have many other co-factors and beneficial constiuents present. For example, the amla berry, also known as the Indian gooseberry, is very high in vitamin C and is a well known herb.
However the doses of vitamin C used in these studies are quite high and may not be practically achievable through oral consumption of a natural product.
We have a forum thread about vitamin C if you want to discuss the topic further.