Fig. 1. Plasma vitamin C concentrations in free-living subjects (n = 11) immediately prior to and after a two-week diet intervention: 8 fl.oz. orange juice daily (66 mg ascorbic acid), 16 fl.oz. orange juice daily (122 mg ascorbic acid); and 1 vitamin C supplement daily (69 mg ascorbic acid/capsule). All subjects received each two-week treatment proceeded by a two-week washout period in a randomized, crossover fashion. There were no significant differences among groups at pre-intervention or at post-intervention. An asterisk denotes a significant change from pre-intervention (p < 0.05).