Basics
What is vitamin C also known as?
Ascorbic acid if you work in chemistry
Ascorbate if you work with human physiology 😀
Roles of Vitamin C
Collagen synthesis, involved in all protein structures pretty much all over the body, in tissues and in organs, including the heart.
Collagen is one of the most important proteins for structure in the body. If you can not synthesise collagen you will get scurvy. The body breaks down, you become hemorrhagic.
It has both an antioxidant role (a chemical agent that donates electrons, to positive physical charges, rendering free radicals inert)
And a pre-oxidant action (can do the opposite of the above in the presence of high levels of metal ions) Vitamin C accepts electrons from metal ions.
It plays a role in the regulation of hypoxia-inducible factor 1a (HiF1alpha)
Protective role, senses cells are running in a hypoxic state (with low oxygen) and HiF1a moves in to destroy these cells.
Recommended levels
Mainstream considers advice considers 10mg per day, which is 10uM plasma level (10 micro molar) to be enough. Allegedly this amount is needed to prevent scurvy although you’d need much much lower levels.
Vitamin C is almost entirely transported by the GLUT4 transporter, therefore it competes with glucose for transport. So they compete with each other.
So if you have high levels of blood glucose it will compete with vitamin C to enter the cells. A low carb diet will mean much less competition for the GLUT 4 transporter and therefore it would seem that you’d require less vitamin C as it is more absorbable.
URIC ACID
The antioxidant effect of vitamin C can also be performed by uric acid. It may even be more efficient in this role.
Vitamin C is metabolised to oxalate which Uric acid does not. Some people believe you can not overdose on Vitamin C as it is water soluble and it will be urinated out but this is not straightforward, as it does appear Vitamin C can metabolise down to oxalate in excess.
The gene for the enzyme to produce ascorbate by a metabolic pathway has been knocked out in all humans on the planet which points to a negative pressure on the body’s evolution for a good reason.