Vitamin E

Also known by these names

  • Tocopherol (alpha, beta, gamma and delta)
  • Tocotrienol (alpha, beta, delta and gamma)
  • RRR-alpha-tocopherol (synthetic)

Vitamin E is a natural antioxidant found in the following foods:

  • Eggs
  • Nuts
  • Green leafy vegetables
  • Wheat germ
  • Whole grains
  • Plant oils, especially from rice bran, sunflower, safflower, cottonseed and palm

Key Points

  • Vitamin E is a generic term for multiple natural and synthetic compounds, all of which are antioxidants.
  • BCCT is interested in vitamin E because some forms may have anticancer properties.
  • Vitamin E may reduce side effects of some conventional cancer therapies.
  • Vitamin E is included in a number of integrative care cancer protocols.
  • No published clinical trials to date describe using vitamin E alone as an anticancer therapy.
  • Vitamin E has low toxicity and is usually well tolerated in low doses.
  • Vitamin E can cause side effects as well as react with some prescription drugs, including chemotherapy drugs.
  • Vitamin E is contraindicated in some medical conditions. Caution and medical supervision are advised.
  • Using vitamin E and other antioxidant supplements for cancer is complex, and the evidence is mixed. BCCT advises working with an integrative oncologist, naturopathic oncologist or other clinician with expertise in using supplements in cancer.

Vitamin E is also available in supplement form.

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Treating the Cancer

Working against cancer growth or spread, improving survival, or working with other treatments or therapies to improve their anticancer action

No reported clinical trials have used vitamin E as a stand-alone  anticancer treatment. Most of the studies in humans look at its use in combination with drugs or in combination with conventional chemotherapy or radiotherapy.

Lab and Animal Evidence

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Managing Side Effects and Promoting Wellness

Managing or relieving side effects or symptoms, reducing treatment toxicity, supporting quality of life or promoting general well-being

Clinical Evidence

Use in combination with drugs or in combination with conventional chemotherapy or radiotherapy shows that vitamin E may reduce side effects such as oral mucositis and peripheral neuropathy, as shown in several small studies.12 Some evidence shows reduced hot flashes during breast cancer treatment with use.13

Antioxidants including vitamin E may protect against cisplatin-induced toxicity in the kidneys (nephrotoxicity) and the ears (ototoxicity).14

Reducing Risk

Reducing the risk of developing cancer or the risk of recurrence

The impacts of vitamin E on cancer risk are complex and vary by the form of vitamin E and by the status of other nutrients and genetic backgrounds of individuals.

Dietary Vitamin E

Higher amounts of dietary vitamin E consumed by prostate cancer patients of European-American descent were associated with less aggressive forms of the disease. This was not seen in patients of African-American descent.15

Results published in 2014 of a large-scale randomized trial in men showed vitamin E and C supplementation had no immediate or long-term effects on the risk of total cancers, prostate cancer, or other site-specific cancers.16

Serum Levels of Vitamin E

Findings with prostate cancer

  • Progressively higher PSA scores with decreasing serum levels of vitamin E with  in a small study17
  • Decreased risk for developing prostate cancer with higher serum alpha-tocopherol levels, with a higher association of decreased risk for advanced prostate cancer and a greater association among those taking alpha-tocopherol supplements18
  • Reduced total prostate cancer risk and aggressive cancer risk in current smokers with higher alpha-tocopherol or gamma-tocopherol levels, with some evidence of differences among genotypes19

Supplements

Studies have found inconsistent evidence of effects of vitamin E supplementation on prostate cancer risk:

  • Increased risk among healthy men in a large study taking synthetic all rac-alpha-tocopheryl acetate supplements,20 limited to those with lower baseline selenium levels, with indications of differences by genetic types21
  • Increased risk from alpha-tocopherol supplementation but decreased risk with gamma-tocopherol use22
  • Reduced risk for both prostate cancer and advanced cancer with alpha-tocopherol in a pooled analysis, but no association with gamma-tocopherol23

Analyses of data propose that risks associated with vitamin E may vary by genotype of patients or by the specific form of vitamin E (alpha-tocopherol versus gamma-tocopherol, for instance)24

A 2017 review indicates that studies focusing on alpha-tocopherol supplements may be missing important effects from other forms of vitamin E. The authors of this review found that accumulating research results show that other forms of vitamin E—such as gamma-tocopherol, delta-tocopherol, gamma-tocotrienol, and delta-tocotrienol—have far superior cancer-preventive activities than does alpha-tocopherol. Evidence strongly indicates that these lesser-known vitamin E forms are effective agents for cancer prevention or as adjuvants for improving prevention of cancer.25

Integrative oncologist and BCCT advisor Donald Abrams, MD, recommends against use of vitamin E supplements.26

Cautions

Low doses of vitamin E are considered relatively nontoxic. However, vitamin E can cause side effects and drug interactions, some of which can be serious. Daily levels at or above 400 IU are not recommended. Higher levels have been associated with increased mortality:

  • Doses greater than 400 IU/day increased all-cause mortality, mostly in patients with chronic diseases. Higher levels of supplements were associated with greater mortality.27
  • No increase in mortality at doses up to 800 IU/day was seen in apparently healthy people.28
  • Increased mortality was found in mixed studies of healthy individuals and those with diseases.29

Some researchers express concerns about vitamin E's interfering with chemotherapy and radiation therapy.30

Most vitamin E supplements contain only alpha-tocopherol. Integrative oncologist and BCCT advisor Keith Block, MD. cautions against giving alpha-tocopherol alone, as this may deplete the body of other important components of vitamin E.31

Lung cancer patients, especially former or current smokers, “should avoid megadoses of particular antioxidants such as vitamin E and beta-carotene, as well as vitamin A . . . some studies have indicated risks to these patients and to smokers from pro-oxidants formed in the hazardous internal environment that smoking causes.”32

Consult your pharmacist for interactions, and discuss using vitamin E with your doctor. See the following sources for more information on specific side effects, cautions and contraindications:

Access

Vitamin E is widely available in food sources and in supplements.

Dosing

BCCT does not recommend therapies or doses, but only provides information for patients and providers to consider as part of a complete treatment plan. Patients should discuss therapies with their physicians, as contraindications, interactions and side effects must be evaluated.

As noted above, levels of active ingredients of natural products can vary widely between and even within products. See Quality and Sources of Herbs, Supplements and Other Natural Products.

Although no optimal vitamin E dose during or after cancer treatment has been established, suggested dosages are listed in these sources:

Integrative Programs, Protocols and Medical Systems

For more information about programs and protocols, see our Integrative Programs and Protocols page.

Integrative oncology clinicians such as Keith Block, Dwight McKee and Lise Alschuler incorporate vitamin E supplementation into care either during active cancer treatment or after treatment care (or both) to prevent recurrence or secondary cancers.

Commentary

According to Raymond Chang, MD, tocotrienols are much more potent than the tocopherol form of E vitamins, especially gamma-tocotrienol, and especially against cancer.39

Integrative oncologist and BCCT advisor Keith Block, MD: “Avoid high doses of single antioxidant supplements . . . Labile antioxidants—which include vitamins A, C and E, selenium and beta-carotene—can change into pro-oxidants . . . Thus they can increase the oxidative stress of your terrain and, if used without proper supervision, enhance the growth and spread of cancer cells. Used in the right dosages and combinations, however, they can help control malignancy.”40 Dr. Block advises using antioxidants like vitamin E in a mix of diverse antioxidants to promote a synergistic effect.41

Nutrition Advisor Karen Collins, MS, RDN, CDN, FAND,  American Institute for Cancer Research, July 26, 2019: There are multiple reasons to be cautious about alpha-tocopherol supplements much beyond RDA level. I cannot find evidence of an effect on absorption of tocotrienols and other tocopherols, but it has been known for many years that high levels of alpha-tocopherol intake tend to decrease blood and tissue levels of gamma-tocopherol. (I'm not sure of the reason—perhaps through effects on absorption from the gut, but perhaps on saturation of metabolic enzymes, preferential saturation of carriers within the body, or other mechanisms.) 

While there is great interest in the potential of tocopherols and tocotrienols beyond alpha-tocopherol for anticancer effects, these ideas are largely based on in vitro and animal studies. There is a big leap from these kinds of studies to human application, which need to consider dose, bioavailability, potential differences among human populations.

However, it's important to think more broadly about your question, too. Our antioxidant defense network (from exogenous sources and endogenous elements within our body) interact in many ways. So setting any single element high may have ramifications on others. Selenium is one example, which is noted in the references I share below and is still coming up in studies as recently as May.

Perhaps this summary of research and recommendations written for health professionals will be helpful to you: National Institutes of Health Vitamin E: Fact Sheet for Health Professionals. It focuses on alpha-tocopherol, since that is the only form for which we have established recommended intake at this time. The reason I recommend it for your review is that it provides important perspective on potential for excess. Although the Tolerable Upper Intake Levels (set to accompany the RDAs) were developed based on avoidance of hemorrhagic effects, evidence from studies like the SELECT trial show that problems such as increased risk of prostate cancer can occur at levels above the RDA but well below that upper limit. (Remember back in the day when cardiologists were excited to recommend 400 IU to all their heart patients??)

There is also a version written for the public, in case you'd like to link to it in what you're creating: Vitamin E:
Fact Sheet for Consumers.

Another reference that may help explain the strong findings about the dangers of antioxidant supplements during cancer treatment: Avoiding Antioxidant-Drug Interactions During Cancer Treatment.

My bottom line: Concern about interactions of alpha-tocopherol supplements with tocotrienols and other tocopherols is only one of several reasons to be concerned about supplementation beyond the RDA, especially well beyond it. 

Non-cancer Uses of Vitamin E

BCCT has not reviewed the effectiveness of this therapy for non-cancer uses.

  • Preventing progression of Alzheimer’s disease
  • Treating arthritis
  • Preventing cardiovascular complications of diabetes
  • Treating fatty liver diseases
  • Reducing hot flashes

Written by Laura Pole, RN, MSN, OCNS, and reviewed by Nancy Hepp, MS; most recent update August 21, 2019. Note: BCCT has not conducted an independent review of research of vitamin E. This summary draws primarily from CAM-Cancer’s Summaries and the Memorial Sloan Kettering Cancer Center’s About Herbs.

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