There is now copious evidence that Vitamin C benefits people with impaired immune function, whether that impairment is the result of disease or simply of aging. In patients with frequent skin infections, for example, who had known impairment in neutrophil tracking and killing of microorganisms, Vitamin C was as effective as a powerful immune-regulating drug, Levamisole, at improving neutrophil function and producing long-lasting remission. But unlike Levamisole, which produced severe side effects causing 8% of subjects to drop out of the study, no patients in the Vitamin C arm dropped out. Similar improvements in neutrophil function, and dramatic clinical recoveries, were seen in patients with recurrent furunculosis (boils), on a dose of 1,000 mg per day.