A recent study on obese and overweight adults showed vitamin C has similar vascular benefits to exercise.
People who are overweight have more endothelin-1, a protein that constricts small blood vessels. Exercise can reduce the activity of this protein.
A daily dose of 500mg of vitamin C provides endothelin-thinning action similar to walking.
Although vitamin C does not replace exercise, this study indicates it can improve vascular functioning in the small blood vessels through supplementation.
P.S. Studies also show vitamin C may help with connective tissue repair, boost the immune system in athletes after rigorous training and reduce the effects of exercise-induced asthma.
Note: "Vitamin C stays in the body for only twelve hours." - Dr. Michael Eades, M.D.