Vitamin E supplementation has not been shown to have significant benefit.[41] Vitamin E does not decrease mortality in adults, even at large doses,[42] and high-dosage supplementation may slightly increase it.[43][44] It does not improve blood sugar control in an unselected group of people with diabetes mellitus[42] or decrease the risk of stroke.[45] Daily supplementation of vitamin E does not decrease the risk of prostate cancer and may increase it.[46] Studies on its role in age-related macular degeneration are ongoing, though if it is of a combination of dietary antioxidants used to treat the condition it may increase the risk.[47]
Vitamin E, along with β-carotene and vitamin C, has no protective effect on reducing the risk of cataract, cataract extraction, progression of cataract, and slowing the loss of visual acuity.[48]