Objective: To study the effects of organic selenium supplementation on glutathione peroxidase (GPx) activities.
Methods: Randomized controlled trials (RCT) published from January 1988 to December 2010 on the relationship between organic selenium supplementation and GPx activities were collected. Meta-analysis was applied to estimate the combined standardized mean difference (SMD) and 95% confidence interval (95% CI).
Results: A total of 10 RCTs were included. The number of studies observing GPx activities in plasma, erythrocyte and platelet was 8, 5 and 5, respectively. Compared with the controls, the combined SMD (95% CI) of GPx activities in plasma, erythrocyte and platelet of subjects supplemented with organic selenium was 0.46 (0.09 - 0.83), 0.36 (0.02 - 0.69) and 0.56 (-0.02 - 1.15).
Conclusion: Supplementation with organic selenium increases GPx activities in healthy adults.