Limitations to current science

Some investigations have shown a potential blunting of skeletal muscle adaptations to endurance training with combined vitamin E and vitamin C supplementation.^11-13 There is currently no convincing evidence that vitamin E supplements alone impair exercise-related adaptations in humans. While vitamin E is generally considered ‘safe’ even with intake well above RDI¹⁴, a meta-analysis of clinical trials of vitamin E supplementation across a range of different clinical conditions reported that adults who consume ≥400 IU/day were 6% more likely to die of any cause compared to no supplementation.¹⁵ Other meta-analyses of human RCTs have found that there is no risk of increased CVD mortality or all-cause mortality at doses of up to 800 IU/day.^16-17