Re: vitamin C DOES cross blood brain barrier, however...

Ascorbic acid had the chemical formula C6H8O6.
Dehydroascorbate's formula is C6H6O6 or 2 Hydrogens less.
When you dissolve ascorbic acid in water it dissociates into H+ and ascorbate C6H7O6-. The minus indicates ascorbate has an an extra electron, is "reduced" due to the extra negative electron. We call this potential electron donor an antioxidant.
It seems to me that simply bubbling oxygen through the ascorbate solution will remove the extra electron plus another H ie oxidize it to dehydroascorbate. I believe this occurs in your intestine when you consume ascorbate. Any biochemists disagree? Tweet