Vitamin C Twice a Day Enhances Health‪.‬

1. INTRODUCTION In 1956, Denham Harman, founder of AGE, proposed the free radical (ROS) theory of aging [1]. Linus Pauling proposed megadoses of the water-soluble antioxidant vitamin C (ascorbic acid, AA) to trap free radicals, recommending dosages up to 16 g per day [2]. Harman and Pauling's efforts moved the nutrition standards from levels that merely prevent short-term deficiency diseases to higher levels that reduce the risk for chronic disease associated with aging. For nutrition studies to identify risk for chronic disease, it is helpful to identify biomarkers that reflect disease-generating processes. For instance, oxidized DNA resulting from free radical damage may be a biomarker for future cancer.