Men with low baseline vitamin C levels (around 35 µmol/L) had lower VO2 max compared to those with high levels (around 78 µmol/L), but supplementation with 1g/day vitamin C for 30 days reduced oxidative stress biomarkers in the low-level group.

“the 10 men having the lowest levels about 35 micro moles per liter and the 10 men with the highest levels about 78 micro moles per liter were assigned to two groups the 20 participants performed aerobic exercise to exhaustion before and after 30 days of supplementation with either one gram of vitamin C or lactose Control at the end of the study the men with low baseline vitamin C levels had lower vo2 Max levels compared to the high vitamin C group however the men with the low baseline levels did show some improvement in that they had reduced biomarkers of oxidative stress”