Practical application of this? Perhaps only in hyperglycemia? I’m not doubting that there is some level of competition, only asking what the significance of this is. For example, if a normal diet needs 10mg/day C, how many mg would be needed for a low carb diet? Is it actually a relevant amount less? I am not aware of any research showing this.https://www.ncbi.nlm.nih.gov/pubmed/16118484/
Oxidative stress has been considered to be a common pathogenetic factor of diabetic nephropathy. But the reason why renal cells are susceptible to oxidative injury in diabetes is not clear. Vitamin C plays a central role in the antioxidant defense system and exists in two major forms. The charged form, ascorbate, is taken up into cells via sodium-dependent facilitated transport. The uncharged form, dehydroascorbate, enters cells via glucose transporter and is then converted back to ascorbate within these cells. Because dehydroascorbate and glucose compete for glucose transporters, hyperglycemia will exclude vitamin C from the cell and resulted in a decreased antioxidant capacity in some cell type that is dehydroascorbate dependent. As such, we hypothesized that some renal cells were dehydroascorbate dependent and the susceptibility of renal cells to glucose-induced injury was mediated by hyperglycemic exclusion of dehydroascorbate uptake through competing for glucose transporter. The aims of the present study were to determine whether tubular epithelial cell was dehydroascorbate dependent and the effect of dehydroascorbate on the production of reactive oxygen species in cells incubated by high glucose.
I’m not sure it even matters though, as the most likely reason why Inuits don’t get scurvy isn’t because not eating carbs reduces their need for C, but that their diet provides enough C to prevent it anyway.