[evan_au (OP)]

Most species of animals can synthesise their own Abscorbic Acid (Vitamin C); it plays a major role in maintaining collagen in skin, wound healing, and spine maintenance. In fact, everything that falls apart in the disease "scurvy".

However, humans and most primates have a corrupted genetic pathway to synthesise Abscorbic Acid. This makes it a "Vital Amine" or "Vitamin" in the human diet.

Could we restore the genetic pathway to produce Abscorbic acid, making "Vitamin C" no longer a "Vitamin"?

As a side-benefit, continuous high levels of this antioxidant may reduce the incidence of cancer.

[smart]

This might interest you: https://geneticliteracyproject.org/2014/02/11/the-latest-on-rewriting-genomes-humans-included/

[Bored chemist]

"Could we restore the genetic pathway to produce Abscorbic acid, making "Vitamin C" no longer a "Vitamin"?"
Perhaps, but it wouldn't take me long to find a dozen better things we could do with that ability.

"As a side-benefit, continuous high levels of this antioxidant may reduce the incidence of cancer."
Or not.
http://www.nature.com/nature/journal/v461/n7260/full/nature08268.html

[puppypower]

Another way to look at the human loss of the ability to make vitamin C may be connected to environmental interaction. Being omnivores, this would expose humans to sufficient external sources of Vitamin C, to cause its synthesis to become redundant at an internal level. It is sort of like clothing reducing the need for skin pigmentation.

This puts a new spin on natural selection where the brain leads and selection becomes based on choices made by the group. If they all choice to migrate toward the cold, selection has a new path.