What potential health issue may occur from supertherapeutic doses of Vitamin C?

Supertherapeutic doses of Vitamin C can lead to hyperoxalosis, which is an increased level of oxalate in the urine. This condition can result in the precipitation of calcium oxalate crystals in the kidneys, subsequently increasing the risk of kidney stone formation and acute kidney injury (AKI).

Vitamin C is metabolized into oxalate in the body, and when taken in excessive amounts, especially in individuals with existing kidney issues or those predisposed to kidney stones, the oxalate can build up. This accumulation can overwhelm the kidneys' ability to excrete it, leading to the various renal complications associated with hyperoxalosis.

In the context of the other choices, while dehydration, gout flare-ups, and cardiovascular events can pose health risks, they are less directly correlated with the specific metabolic effects of high Vitamin C intake compared to the clear renal implications of hyperoxalosis. Thus, the potential health issue that is most pertinent and directly associated with supertherapeutic doses of Vitamin C is hyperoxalosis leading to acute kidney injury.