Vitamin E has been investigated as an adjunct therapy to reduce certain side effects associated with chemotherapy, particularly chemotherapy-induced peripheral neuropathy (CIPN). The rationale stems from vitamin E’s antioxidant properties, which may help protect nerve cells from oxidative damage caused by some chemotherapeutic agents (such as cisplatin or paclitaxel). Several small randomized controlled trials and meta-analyses have examined this effect, with some studies suggesting that vitamin E supplementation (typically at doses of 300-600 mg/day) may reduce the incidence or severity of CIPN without reducing chemotherapy effectiveness.

However, the overall quality of evidence is limited. Some studies show benefit, while others do not demonstrate a significant effect, and there are concerns that antioxidants like vitamin E could theoretically interfere with the oxidative mechanisms by which some chemotherapies kill cancer cells. Major oncology guidelines, such as those from the American Society of Clinical Oncology (ASCO), do not currently recommend vitamin E for routine prevention or treatment of chemotherapy side effects due to insufficient and inconsistent evidence.

In summary, while there is a plausible scientific rationale and some preliminary clinical support for vitamin E in reducing certain chemotherapy side effects (notably neuropathy), the evidence base is modest (rating: 2/5). Patients should consult with their oncology team before starting vitamin E during chemotherapy.