Short-term, Moderate Dosage Vitamin E Supplementation May Have No Effect on Platelet Aggregation, Coagulation Profile, and Bleeding Time in Healthy Individuals

Objective To investigate the in vivo effect of short-term, moderate dosage synthetic dl-α-tocopherol acetate supplementation on platelet aggregation, coagulation profile, and simulated bleeding time in healthy individuals. α-tocopherol is the most biologically active isomer of Vitamin E, traditionally promoted as an antioxidant and therapeutic agent in cardiovascular disease. In vitro studies have suggested that α-tocopherol plays a role in the inhibition of platelet aggregation. However, further investigations into the effect of α-tocopherol on bleeding in vivo have not duplicated these findings. Materials and methods A total of 42 healthy volunteers complied with a 2-week abstinence period from the use of anti-platelet agents followed by determination of baseline platelet aggregation properties and coagulation studies using citrated whole blood. Moderate dosage Vitamin E (800 IU of dl-α-tocopherol acetate) was then self-administered for 14 days with reevaluation of platelet aggregation and coagulation profile, and simulated bleeding time after 14 days of Vitamin E supplementation. Results Forty subjects completed the 4-week study period. All 40 subjects demonstrated normal baseline coagulation studies and all had collagen-stimulated platelet aggregation assessment performed in triplicate. After Vitamin E supplementation, no significant difference was demonstrated in any study parameter. Conclusions Dietary supplementation with moderate dosage synthetic dl-α-tocopherol acetate did not significantly prolong bleeding or platelet aggregation in vivo . The affect of Vitamin E on platelet aggregation in vitro does not appear to be reproducible in vivo . Therefore, peri-operative discontinuation of Vitamin E may not be necessary.