effect of vitamin c on salivary total antioxidant capacity in smokers

this study was designed to elucidate the effect of ascorbic acid on salivary total antioxidant capacity in smokers. in this single blind crossover clinical trial, the whole unstimulated saliva of 30 smokers, who were randomly divided into two groups, was collected. in the first phase after the saliva collection, one group of patients took 500 mg of vitamin c powder, for 3 weeks. then, saliva of all patients was collected. after a one-week wash-out period, vitamin c was given to the other group. the collection of saliva was done after 3 weeks. total antioxidant capacity was measured. statistic evaluation was performed by repeated measured anova, independent sample t-test and covariate test. the mean of total antioxidant capacity with and without using vitamin c was 0.511 ± 0.155 (u/ml) and 0.555 ± 0.171 (u/ml), respectively. this variability was not significant (p = 0.605). oxidative stress from cigarette smoke was not decreased significantly with using vitamin c.