qui riportano un quadro completo degli studi, la questione è controversa ma tendenzialmente l'azione prevelente è antiossidante
http://www.fasebj.org/content/13/9/1007.full
queste le conclusioni
CONCLUSION
Does vitamin C act as a pro-oxidant under physiological conditions? The answer appears to be ‘no’. Of the 44 in vivo studies discussed (Tables 2#8659; 3#8659; 4)#8659; , 38 showed a reduction in markers of oxidative DNA, lipid, and protein damage, 14 showed no change and only 6 showed an increase in oxidative damage after supplementation with vitamin C. Several of the studies showed a combination of effects depending on the study systems or experimental design. Even in the presence of iron (summarized in Table 5#8659; ), vitamin C predominantly reduced in vivo oxidative damage, despite its well known pro-oxidant properties in vitro in buffer systems containing iron. In more complex and physiologically relevant in vitro systems, such as isolated or cultured cells (Table 2)#8659; and biological fluids (Tables 3#8659; and 4)#8659; , an antioxidant role, or no effect of vitamin C, predominated over a pro-oxidant role. Studies that report a pro-oxidant role for vitamin C need to be evaluated carefully as to their choice of biomarkers, methodology, study system, and experimental design to rule out any oxidation artifacts. It is hoped that these four important considerations will be taken into account in all future studies of the role of vitamin C in oxidative damage.