February 22, 2014

The Research Behind Vitamin E

Bottom Line Monograph
Vitamin E has been proposed for the prevention or treatment of numerous health conditions, often based on its antioxidant properties. Ongoing research is investigating its use in numerous diseases, particularly in cancer and heart disease. Concerns have been raised about the safety of vitamin E supplementation, particularly in high doses. Evidence suggests that regular use of high-dose vitamin E supplements may increase the risk of death from all causes by a small amount, although human research is conflicting.

Related Terms

All rac-alpha-tocopherol, alpha-tocopherol acetate, alpha-tocopheryl acetate, alpha-tocotrienol, antisterility vitamin, beta-tocopherol, beta-tocotrienol, d-alfa-tocopherol acetate, d-alpha-tocopherol, d-alpha-tocopheryl, d-alpha-tocopheryl acetate, d-alpha-tocopheryl succinate, d-beta-tocopherol, d-delta-tocopherol, delta-tocopherol, delta-tocotrienol, d-gamma-tocopherol, d-tocopherol, d-tocopheryl acetate, dl-alpha-tocopherol, dl-alpha-tocopheryl acetate, dl-tocopherol, gamma-tocopherol, gamma-tocotrienol, mixed tocopherols, RRR-alpha-tocopherol, Spondyvit®, tocofersolan, tocopherol, tocopheryl succinate, tocotrienol, tocotrienol concentrate.

Background

  • Vitamin E is a fat-soluble vitamin with antioxidant properties. Vitamin E exists in eight different forms (isomers): alpha-, beta-, gamma-, and delta-tocopherol; and alpha-, beta-, gamma-, and delta-tocotrienol. Alpha-tocopherol is the most active form in humans.
  • Dosing and daily allowance recommendations for vitamin E are often provided in alpha-tocopherol equivalents (ATEs) to account for the different biological activities of the various forms of vitamin E, or in international units (IU), which food and supplement labels may use. The conversion factor is 1mg of an ATE=1.5 IU.
  • Vitamin E supplements are available in natural or synthetic forms. The natural forms are usually labeled with the letter "d" (for example, d-gamma-tocopherol), whereas synthetic forms are labeled "dl" (for example, dl-alpha-tocopherol).
  • Foods that contain vitamin E include eggs, fortified cereals, fruit, green leafy vegetables (such as spinach), meat, nuts, nut oils, poultry, vegetable oils (corn, cottonseed, safflower, soybean, sunflower), argan oil, olive oil, wheat germ oil, and whole grains. Cooking and storage may destroy some of the vitamin E in foods.
  • Vitamin E has been proposed for the prevention or treatment of numerous health conditions, often based on its antioxidant properties. However, aside from the treatment of vitamin E deficiency (which is rare), there is a lack of clearly proven medicinal uses of vitamin E supplementation beyond the recommended daily allowance. There is ongoing research on its use in numerous diseases, particularly in cancer and heart disease.
  • Concerns have been raised about the safety of vitamin E supplementation, particularly in high doses. An increased risk of bleeding has been proposed, particularly in patients taking blood-thinning agents such as warfarin, heparin, or aspirin, and in patients with vitamin K deficiency. Evidence suggests that regular use of high-dose vitamin E supplements may increase the risk of death from all causes by a small amount, although human research is conflicting. Caution is warranted.
  • Scar prevention is another controversial use for vitamin E. While this use is commonly practiced, there is a lack of evidence for its efficacy. Because of a risk of contact dermatitis, some researchers have advised against the use of this therapy.

Scientific Evidence

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Vitamin E deficiency

Vitamin E deficiency is rare and may occur in people with diminished fat absorption through the gut (due to surgery, Crohn's disease, or cystic fibrosis), malnutrition, very-low-fat diets, or several specific genetic conditions (abetalipoproteinemia, "ataxia and vitamin E deficiency" [AVED]); in very-low-birthweight premature infants; or infants taking unfortified formulas. Vitamin E supplementation is accepted as an effective therapy for vitamin E deficiency to halt progression of complications. Diagnosis of this condition and its management should be under the care of a physician and nutritionist.

Grade: A

Age-related macular degeneration

Like other antioxidants, vitamin E has been suggested to prevent, slow progression, or improve macular degeneration. The scientific evidence in this area is not conclusive, although there is some suggestion that vitamin E alone, or in combination with beta-carotene, may not be beneficial. Additional research is warranted before a clear conclusion can be drawn.

Grade: C

Allergic rhinitis

Although antioxidants are thought to aid in reducing the nasal symptoms of allergies, vitamin E intake may not be effective. Although this has not been well studied in humans, research has demonstrated the potential use of gamma-tocopherol in allergic rhinosinusitis. However, current evidence is limited, and additional research is warranted.

Grade: C

Altitude sickness

Vitamin E may offer some benefits in exposure to high altitude. Antioxidant supplementation (vitamin E with beta-carotene, vitamin C, selenium, and zinc) may improve ventilatory threshold at high altitudes. However, antioxidants may not reduce inflammation after exercise at high altitudes. Additional research is warranted.

Grade: C

Amyotrophic lateral sclerosis (ALS)

Nutritional interventions have been investigated for the prevention and treatment of neurodegenerative diseases such as ALS. There is unclear evidence with respect to vitamin E for treatment of ALS. Additional research is warranted.

Grade: C

Anemia

Antioxidants have been studied for the prevention and treatment of various types of anemia. Studies of vitamin E supplementation for anemia have yielded mixed results. Additional research is warranted.

Grade: C

Angina

Vitamin E has been suggested and evaluated in patients with angina (chest pain), although its possible benefits remain unclear. Further evidence is necessary before a clear conclusion can be drawn. Patients with known or suspected angina should be evaluated by a physician.

Grade: C

Antioxidant

Vitamin E possesses antioxidant activity, but the clinical effects of antioxidant protection by vitamin E are not clear in humans. The American Heart Association has recommended obtaining antioxidants such as vitamin E by eating a well-balanced diet high in fruits, vegetables, and whole grains, rather than from supplements, until further scientific evidence is available.

Grade: C

Asthma

In schoolchildren, lower levels of vitamin E have been associated with poorly controlled asthma. Maternal intake of vitamin E during pregnancy has been associated with reduced rates of asthma and wheeze in children. However, there is evidence that vitamin E supplementation may not provide benefits in individuals with asthma. Additional research is warranted.

Grade: C

Atherosclerosis

Vitamin E has been proposed to have a role in preventing or reversing atherosclerosis (clogging and hardening of arteries) by inhibiting oxidation of low-density lipoprotein (or "bad") cholesterol. Studies have suggested that a high dietary intake of vitamin E and high blood concentrations of alpha-tocopherol are associated with lower rates of heart disease. This area remains controversial, and further research is required.

Grade: C

Bladder cancer

There is preliminary evidence of possible benefits of long-term vitamin E supplementation to reduce the risk of mortality in bladder cancer patients, although additional research is necessary before a clear conclusion can be reached.

Grade: C

Breast cancer

Vitamin E has been suggested as a possible therapy for the prevention or treatment of breast cancer. Published studies have included measurement of vitamin E levels, laboratory experiments, and population studies. Evidence remains inconclusive, and no clear conclusion can be drawn at this time.

Grade: C

Breast cancer-related hot flashes

A study of oral vitamin E reports a very small reduction in hot flash frequency (approximately one less hot flash daily), but with no preference among patients for vitamin E over placebo. Further research is required.

Grade: C

Cancer prevention (general)

Evidence from a well-conducted randomized controlled trial (the Women's Health Study) reports no reduction in the development of cancer with the use of natural-source vitamin E taken daily. Previously, there have been laboratory, population, and other human trials examining whether vitamin E is beneficial in preventing various types of cancer, including prostate, colon, or stomach cancer. Results of these prior studies have been variable. Additional research is warranted.

Grade: C

Cancer treatment

There is a lack of reliable scientific evidence that vitamin E is effective as a treatment for any specific type of cancer. Caution is merited in people undergoing treatment with chemotherapy or radiation, because it has been proposed that the use of high-dose antioxidants may actually reduce the anticancer effects of these therapies. This remains an area of controversy, and studies have produced variable results. High doses of vitamin E may also cause harm in cancer patients. Patients interested in using high-dose antioxidants such as vitamin E during chemotherapy or radiation should discuss this decision with their medical oncologist or radiation oncologist.

Grade: C

Cardiovascular disease in dialysis patients

It has been suggested that hemodialysis patients may be under increased oxidative stress and therefore may benefit from the chronic use of antioxidants (particularly for the reduction of risk of heart disease). There is some research on the use of high-dose chronic vitamin E in dialysis patients for heart disease prevention, although its benefits or risks remain unclear in this population. Recent concern has been raised that regular use of high-dose vitamin E supplements may actually increase the risk of death from all causes by a small amount, although this remains an area of controversy and active investigation. Additional research is warranted.

Grade: C

Cataract prevention

There is conflicting evidence regarding the use of vitamin E to prevent cataracts. Although some studies across populations have suggested some protective effects (which may take up to 10 years to yield benefits), other studies in humans have reported a lack of benefits when used either alone or in combination with other antioxidants. Additional research is warranted.

Grade: C

Chemotherapy-induced neuropathy

Like other antioxidants, vitamin E has been suggested as a therapy to prevent complications due to chemotherapy, such as neuropathy (nerve damage). There is some evidence of benefit, for example, when it is used with cisplatin. However, caution is merited, because it is not known if the use of high-dose antioxidants during chemotherapy may actually reduce the anticancer effects of some chemotherapy agents or radiation therapy. This remains an area of controversy. Patients interested in using antioxidants during chemotherapy should discuss this decision with their oncologist.

Grade: C

Colon cancer prevention

Sufficient scientific evidence is lacking to determine if vitamin E prevents colon cancer. In patients with previous colon cancer, a combination of vitamins A, C, and E has been reported to reduce the risk of developing a new colon cancer, while this effect was not observed in another trial. Preventive benefits have also been suggested in those with no prior colon cancer when vitamin E is used in a multivitamin, but not when used alone. Recent results of the Women's Health Study have reported no overall reduction in cancer risk with daily use of vitamin E, although this study was not large enough to look at colon cancer specifically. Additional research is warranted.

Grade: C

Dementia / Alzheimer's disease

Vitamin E has been proposed and evaluated for the prevention or slowing of dementia (including the Alzheimer's type), based on antioxidant properties and findings of low vitamin E levels in some individuals with Alzheimer's disease. There is some evidence that all-rac-alpha-tocopherol (synthetic vitamin E) is similar in efficacy to selegiline (Eldepryl®) and superior to placebo for slowing cognitive function decline in patients with moderately severe Alzheimer's disease, but no additive effect was observed when used in combination with selegiline. Retrospective data suggest that long-term combination therapy with donepezil (Aricept®) may help slow cognitive decline in patients with Alzheimer's disease. Other research suggests that vitamin E from dietary sources or supplements does not affect the risk of developing Alzheimer's disease or vascular dementia. Overall, the evidence remains inconclusive in his area.

Grade: C

Diabetes mellitus

Vitamin E has been proposed for the prevention of type 1 or 2 diabetes; for the improvement of abnormal sugar control in diabetes; for prevention of platelet dysfunction and atherosclerosis in diabetes; for the correction of vitamin E deficiency in diabetic patients; and for the prevention of diabetic neuropathy, retinopathy, and nephropathy (complications of the eye, kidneys, and nervous system). Vitamin E deficiency has been observed in patients with diabetic foot ulcers. It is not clear that vitamin E is beneficial in any of these areas. Further evidence is warranted before a clear conclusion can be drawn.

Grade: C

Diabetic retinopathy

Micronutrients have been studied for improvement in diabetic retinopathy, and vitamin E has been proposed to reduce oxidative stress related to diabetic complications. However, the evidence of benefit is lacking, and additional research is warranted.

Grade: C

Dysmenorrhea

There is preliminary evidence of possible benefits of vitamin E supplementation to reduce chronic menstrual pain, although additional research is warranted in this area before a firm conclusion can be reached.

Grade: C

G6PD deficiency

Vitamin E supplementation has been studied for the inherited disorder G6PD deficiency, with conflicting evidence. Additional research is warranted before a clear conclusion can be drawn.

Grade: C

Glomerulosclerosis (kidney disease)

It has been suggested that proteinuria (protein in the urine) may be reduced with the use of vitamin E in patients with focal segmental glomerulosclerosis, which is resistant to standard medical management. However, further research is warranted before a clear conclusion can be drawn.

Grade: C

Healing after photorefractive keratectomy

High-dose vitamin E plus vitamin A (taken by mouth) may improve healing of the cornea and improve visual acuity (sharpness) following laser surgery for vision correction. Although this has not been well studied in humans, research suggests that topical vitamin E on the eye may be helpful. Additional research is warranted.

Grade: C

Heart disease prevention

Numerous studies of vitamin E (taken by mouth) have suggested a lack of benefit in the prevention of cardiovascular disease. Also, there is recent evidence to suggest that regular use of high-dose vitamin E increases the risk of death from all causes by a small amount. These conclusions have been criticized by some experts, and it has been suggested to conduct trials in more selective target populations. The Women's Health Study reported a reduction in cardiovascular deaths in women taking vitamin E daily (with 10-year follow-up), but there was no change in total death rate or number of heart attacks or strokes. Further research is required.

Grade: C

Hepatitis (hepatitis C)

In patients with hepatitis C on antiviral therapy, vitamin E has been proposed to prevent inflammation. Additional research is warranted to examine the effects of vitamin E in chronic hepatitis.

Grade: C

Hyperlipidemia

The effects of vitamin E on cholesterol levels and atherosclerosis have been studied in numerous laboratory, population, and clinical trials. It remains unclear if there are clinically meaningful benefits, and it is not known what the effects of vitamin E are compared to (or in combination with) other agents that have been clearly demonstrated as beneficial for lowering lipids. Further research is warranted before a clear conclusion can be drawn.

Grade: C

Immune system function

Studies of the effects of vitamin E supplementation on immune system function have yielded mixed results. Additional research is warranted.

Grade: C

Intermittent claudication

Multiple studies have evaluated the use of vitamin E in patients with peripheral vascular disease, to improve exercise tolerance and intermittent claudication (pain in the legs with walking due to cholesterol buildup in blood vessels). It remains unclear if vitamin E is beneficial in this condition.

Grade: C

Kwashiorkor

Kwashiorkor is a malnutrition disorder caused by a lack of protein in the diet. Treatment involves increasing caloric and protein intake as well as supplementation with vitamins and minerals. It is not clear if vitamin E supplementation is effective in the prevention of kwashiorkor. Further research is warranted.

Grade: C

Liver disease

There is some evidence suggesting possible benefits of vitamin E in the management of steatohepatitis (fatty liver) and nonalcoholic fatty liver disease in children. Further evidence is warranted before a clear conclusion may be drawn.

Grade: C

Mortality reduction

Evidence suggests that regular use of high-dose vitamin E supplements may increase the risk of death from all causes by a small amount, although a different study found no effects on mortality in women who took vitamin E daily. Overall, the results have not shown an association between vitamin E intake and decreased mortality. Further research is warranted in this area.

Grade: C

Oral mucositis

Oral mucositis is a common adverse effect associated with chemotherapy. The effect of vitamin E on oral mucositis is unclear. Further research is warranted.

Grade: C

Osteoarthritis

Oxidative stress is thought to play a role in osteoarthritis. Vitamin E has shown mixed results in reducing symptoms or preventing cartilage loss in osteoarthritis. Additional research is warranted.

Grade: C

Parkinson's disease

Vitamin E has been studied for the prevention or treatment of neurodegenerative disorders such as Parkinson's disease, with mixed results. The scientific evidence is inconclusive in this area, and further research is warranted.

Grade: C

Pre-eclampsia prevention

Vitamin E has been studied for the prevention of pre-eclampsia in pregnant women. However, most studies have been in combination with vitamin C or other micronutrients. Evidence of the efficacy of vitamin E alone is lacking, and further research is warranted.

Grade: C

Premenstrual syndrome (PMS)

Several natural products have been studied for the improvement of premenstrual syndrome symptoms, with mixed results. The scientific evidence for vitamin E is inconclusive in this area, and further research is warranted.

Grade: C

Prostate cancer prevention

The role of vitamin E supplementation for the prevention of prostate cancer is controversial. There are numerous laboratory studies that support possible anticancer properties. However, the results of population research and human research have been mixed.

Grade: C

Respiratory infection prevention

Supplementation with oral vitamin E has shown mixed effects on the incidence, duration, or severity of pneumonia in elderly nursing home residents, and it did not alter patterns of antibiotic use, although there may be a protective effect against colds. Additional research is warranted.

Grade: C

Rheumatoid arthritis

Vitamin E, taken by mouth, does not appear to reduce the risk of developing rheumatoid arthritis in women. Additional research is warranted.

Grade: C

Seizure disorder

Vitamin E has been evaluated as an addition to other drugs used to prevent seizures, particularly in refractory epilepsy. This evidence is inconclusive, and further study is warranted. The management of seizure disorder should be under medical supervision.

Grade: C

Stomach cancer (prevention)

Vitamin supplementation has been proposed to reduce the rate of gastric (stomach) cancer. However, there is some evidence suggesting that vitamin E does not reduce the rates of gastric cancer or precancerous gastric lesions. Additional research is warranted to examine whether vitamin E has any effects on gastric cancer.

Grade: C

Supplementation in preterm and very low birthweight infants

Premature infants are at risk of vitamin E deficiency, particularly when they are born with very low birthweight. There are numerous studies of vitamin E given to premature infants to try to prevent potentially serious complications, such as intraventricular hemorrhage (bleeding into the brain), retinopathy (eye damage), or death. The quality of published research is variable and is not clearly conclusive. Premature infants should be under strict medical supervision. Decisions regarding vitamin supplementation should be made with the infant's physician.

Grade: C

Tardive dyskinesia

Vitamin E has been studied in the management of tardive dyskinesia (involuntary movements) and has been reported to significantly improve abnormal involuntary movements, although the results of existing studies are inconclusive. Vitamin E may be more effective in higher doses and in people who have had tardive dyskinesia for less than five years. Further research is required.

Grade: C

Uveitis

Antioxidants have been studied for uveitis (inflammation of the eye). Four-month oral supplementation with vitamin E had no apparent effect on uveitis-associated macular edema or visual acuity in one small study. Additional research is warranted before a clear conclusion can be drawn.

Grade: C

Venous thromboembolism (VTE)

Data suggest that supplementation with vitamin E may reduce the risk of VTE in women. Those with a prior history or genetic predisposition may particularly benefit. Further research is warranted.

Grade: C

Peyronie's disease

One study did not show significant improvement in pain, curvature, or plaque size in patients with Peyronie's disease (PD) treated with vitamin E, propionyl-L-carnitine, or vitamin E plus propionyl-L-carnitine compared with those treated with placebo. Another trial lacked a difference between vitamin E plus colchicine vs. colchicine alone. Evidence of efficacy for this condition is lacking.

Grade: D

Retinitis pigmentosa

Oral vitamin E does not appear to slow visual decline in people with retinitis pigmentosa and may be associated with more rapid loss of visual acuity, although the validity of this finding has been questioned. Until further evidence is available, vitamin E may not be advisable in this condition. Therapy decisions should be under medical supervision.

Grade: D

Scar prevention

Application of topical vitamin E alone does not appear to reduce surgical wound scarring. Because of a risk of contact dermatitis, some researchers have advised against the use of this therapy.

Grade: D

Stroke prevention

Recent evidence from the Women's Health Study suggests that daily vitamin E supplementation does not reduce the risk of stroke. Prior evidence was indeterminate for stroke prevention or stroke recovery. At this time, based on the best available scientific evidence and recent safety concerns, vitamin E cannot be recommended for this use.

Grade: D

Tradition/Theory

The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

  • Abortifacient, acne, air pollution protection, allergies, alopecia, amiodarone pulmonary toxicity prevention, anti-aging, anticoagulation, athletic performance enhancement, bee stings, benign prostate hyperplasia, beta-thalassemia, blood disorders (porphyria), breast pain/inflammation (mastitis), bronchopulmonary dysplasia in premature infants, bursitis, cardiomyopathy, celiac disease, childhood growth promotion, chorea, congestive heart failure, Crohn's disease, cystic fibrosis, dermatitis, diabetic foot ulcers, diaper rash, digestive enzyme/pancreatic insufficiency, doxorubicin hair loss prevention, Duchenne muscular dystrophy, dyspraxia, energy enhancement, exercise recovery, extravasation, fibrocystic breast disease, frostbite, gastric ulcer, granuloma annulare (topical vitamin E), hair loss, heart attack, hematopoiesis, hereditary spherocytosis, human immunodeficiency virus (HIV), Huntington's chorea/disease, hypertension, impaired glucose tolerance, impotence, infertility (habitual abortion), labor pain, leg cramps, liver spots, lung cancer prevention, male fertility, menopausal symptoms, menstrual disorders, miscarriage, muscle strength, myopathy, myotonic dystrophy, neuromuscular disorders, nitrate tolerance, oral leukoplakia, pancreatitis, peptic ulcers, photoprotection, physical endurance, post-operative recovery (postangioplasty restenosis prevention), postural stability (poor posture), radiation injuries (induced fibrosis), reperfusion injury protection during heart surgery, restless leg syndrome, sexual performance, sickle cell disease, skin aging, skin damage caused by the sun, skin disorders (epidermolysis bullosa), sperm motility, stretch marks, sunburn, thrombophlebitis, transplant rejection prevention (heart), ulcerative colitis, water retention, wound and burn healing.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (over 18 years old)

  • Foods that contain vitamin E include eggs, fortified cereals, fruit, green leafy vegetables (such as spinach), meat, nuts, nut oils, poultry, vegetable oils (corn, cottonseed, safflower, soybean, sunflower), argan oil, olive oil, wheat germ oil, and whole grains. Cooking and storage may destroy some of the vitamin E in foods.
  • Most individuals in the United States are believed to obtain sufficient vitamin E from dietary sources, although individuals with very-low-fat diets or intestinal malabsorption disorders may require supplementation. Recommended dietary allowances (RDAs) for vitamin E are provided in alpha-tocopherol equivalents (ATEs) to account for the different biological activities of the various forms of vitamin E, as well as in international units (IU), which food and supplement labels often use. For conversion, one milligram of an ATE=1.5 IU. The RDA for men or women older than 14 years old is 15 milligrams (or 22.5 IU); for pregnant women of any age, it is 15 milligrams (or 22.5 IU), and for breastfeeding women of any age, it is 19 milligrams (or 28.5 IU).
  • For adults older than 18 years, the tolerable upper limit of dosing for supplementary alpha-tocopherol recommended by the U.S. Institute of Medicine is 1,000 milligrams daily (equivalent to 1,500 IU). This limit recommendation is not altered during pregnancy or breastfeeding.
  • Treatment of vitamin E deficiency should be under medical supervision, tailored to the underlying cause of the deficiency, and may include vitamin E taken by mouth or injected into the vein. If the cause is due to chronic malnutrition and there is no evidence of malabsorption, an oral dose that is 2-5 times greater than the RDA may be considered. If the cause is malabsorption that cannot be corrected, then vitamin E injected into the vein may be necessary. Dosing recommendations vary by the underlying cause.
  • No specific dosing of vitamin E has been established for other conditions, and there is recent evidence suggesting possible adverse health effects from long-term use of daily supplementation with 400 IU or greater daily. Although controversial, the use of long-term vitamin E supplementation should be approached cautiously until further evidence from prospective clinical trials is available. Various doses and durations have been evaluated in clinical trials, although many have not been proven as effective or safe. It is recommended that patients discuss the choice of dosing and duration with a licensed healthcare professional.

Children (under 18 years old)

  • Recommended dietary allowances (RDAs) for vitamin E are provided in alpha-tocopherol equivalents (ATEs) to account for the different biological activities of the various forms of vitamin E, as well as in international units (IU), because food and supplement labels often use this system. For conversion, one milligram of an ATE=1.5 IU. There is no RDA for infants, but there is a recommended adequate intake (AI) for healthy breastfeeding infants 0-6 months old of four milligrams daily (6 IU), and for infants 7-12 months old of five milligrams daily (7.5 IU). The RDA for children 1-3 years old is six milligrams daily (9 IU); for those 4-8 years old, it is seven milligrams daily (10.5 IU); for those 9-13 years old, it is 11 milligrams daily (16.5 IU); for those older than 14 years old, it is 15 milligrams daily (22.5 IU); for pregnant women of any age, it is 15 milligrams (22.5 IU); and for breastfeeding women of any age, it is 19 milligrams (28.5 IU).
  • An upper limit for infants up to 12 months of age has not been established. The tolerable daily upper limit of dosing for those 1-3 years old is 200 milligrams (300 IU); for those 4-8 years old, it is 300mg (450 IU); for those 9-13 years old, it is 600 milligrams (900 IU); and for those 14-18 years old, it is 800 milligrams (1,200 IU).
  • Treatment of vitamin E deficiency should be under medical supervision, tailored to the underlying cause of the deficiency, and may include vitamin E taken by mouth or injected into the vein. If the cause is due to chronic malnutrition and there is no evidence of malabsorption, an oral dose that is 2-5 times greater than the RDA may be considered. If the cause is malabsorption that cannot be corrected, then vitamin E injected into the vein may be necessary. Vitamin E absorption may improve if given with meals, in small doses.No specific dosing of vitamin E has been well established for other conditions.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

  • Avoid with known allergy/hypersensitivity to products that contain vitamin E. Skin reactions such as contact dermatitis and eczema have been reported with topical vitamin E preparations, such as ointments or vitamin E-containing deodorants.

Side Effects and Warnings

  • For short periods of time, vitamin E supplementation is generally considered safe at doses up to the recommended tolerable upper intake level (UL). However, vitamin E is possibly unsafe when used orally at doses exceeding the tolerable upper intake level. The recommended dietary allowance (RDA) obtained through food consumption is considered to be safe and beneficial.
  • The European Food Safety Authority (EFSA) has set the tolerable upper intake level (UL) for adults at 300 milligrams daily, regardless of pregnancy or lactation status. The UL for children ranges from 100 milligrams daily for ages 1-3 years to 260 milligrams daily for ages 15-17 years.
  • Evidence suggests that regular use of high-dose vitamin E may increase the risk of death from all causes by a small amount. These conclusions have been criticized by some experts. Nonetheless, this is the best available scientific evidence currently. Chronic use of vitamin E should be used cautiously, and high-dose vitamin E should be avoided. Acute overdose of vitamin E is very uncommon.
  • In rare cases, vitamin E supplementation has been associated with dizziness, fatigue, headache, weakness, blurred vision, abdominal pain, diarrhea, nausea, or flu-like symptoms (particularly when used in high doses). The risk of necrotizing enterocolitis may be increased with large doses of vitamin E.
  • Use cautiously in patients with cardiovascular conditions. Vitamin E may increase risk of all-cause mortality and incidence of heart failure with doses ≥400 IU daily for over one year.
  • Vitamin E should be used cautiously for long periods of time (>10 years) due to a possible increased risk of hemorrhagic stroke.
  • Use cautiously in patients with skin conditions. Skin reactions, such as contact dermatitis and eczema, have been reported with topical vitamin E preparations, such as ointments or vitamin E-containing deodorants. Pruritus (itching) has been reported following oral supplementation of vitamin E.
  • Use cautiously in patients with kidney impairment. In rare cases, vitamin E supplementation has been associated with gonadal dysfunction and diminished kidney function.
  • Use cautiously in patients with Alzheimer's disease or cognitive decline. In patients with Alzheimer's disease or cognitive decline, vitamin E has been associated with an increase in falls and syncope (fainting).
  • Oral vitamin E should be used cautiously in patients with retinitis pigmentosa, as is does not appear to slow visual decline and may be associated with more rapid loss of visual acuity, although the validity of this finding has been questioned.
  • Use cautiously in patients who smoke. Vitamin E supplementation may transiently increase tuberculosis risk in males who smoke heavily and have high dietary vitamin C intake.
  • Vitamin E should be used cautiously in preterm infants, due to reports of an increased risk of sepsis. Premature infants should be under strict medical supervision. Decisions regarding vitamin supplementation should be made with the infant's physician.
  • Although this has not been well studied in humans, an increased risk of bleeding when used with warfarin (Coumadin®) has been noted. However, other studies have not observed a greater incidence of bleeding. Bleeding has been observed in patients given high repeated doses of intravenous all-rac-alpha-tocopherol (synthetic vitamin E). Avoid in patients with bleeding disorders or those taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary. Reported adverse effects attributed to vitamin E supplementation included minor bleeding and epistaxis (nosebleed).
  • Avoid doses greater than the RDA in pregnant women, due to a possible increased risk of congenital heart defects in offspring.
  • Avoid with known allergy/hypersensitivity to products that contain vitamin E.

Pregnancy and Breastfeeding

  • Many prenatal vitamins contain small amounts of vitamin E. Natural forms of vitamin E may be preferable to synthetic forms. Vitamin E is in the U.S. Food and Drug Administration (FDA) Pregnancy Category A at doses advocated by the FDA. Doses above the RDA level are in FDA Pregnancy Category C.
  • Use beyond the recommended dietary allowance (RDA) level in otherwise healthy pregnant women is generally not recommended. There is otherwise insufficient evidence regarding the safety of higher doses of oral, topical, or injected vitamin E during pregnancy and breastfeeding, and therefore it is not recommended.
  • A combination of vitamins C and E may increase the risk of gestational hypertension (high blood pressure during pregnancy) and low-birthweight infants. Vitamin E use during pregnancy may increase the risk of congenital heart defects.

Interactions

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

  • The amount of bleeding risk associated with vitamin E remains an area of controversy, and caution is warranted in patients with a history of bleeding disorders or those taking blood-thinning drugs such as aspirin, anticoagulants such as warfarin (Coumadin®) or heparin, antiplatelet drugs such as clopidogrel (Plavix®), and nonsteroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).
  • Vitamin E may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
  • Concern has been raised that antioxidants may interfere with some chemotherapy agents (such as alkylating agents, anthracyclines, or platinums), which themselves may depend on oxidative damage to tumor cells for their anticancer effects. Studies on the effects of antioxidants on cancer therapies have yielded mixed results, with some reporting interference, others noting benefits, and most suggesting no significant interaction. However, until additional scientific evidence is available, high-dose antioxidants should be avoided during chemotherapy administration, unless otherwise decided in discussion with the treating oncologist.
  • Cholestyramine (Questran ®), colestipol (Colestid®), orlistat (Xenical®), isoniazid (INH, Lanizid®, Nydrazid®), gefitinib (Iressa®), letrozole (Femara®), and sucralfate (Carafate®) may reduce dietary vitamin E absorption and blood levels of vitamin E. Gemfibrozil (Lopid®) may decrease blood levels of both alpha- and gamma-tocopherol, although the clinical significance of this is not clear. Anticonvulsant drugs such as phenobarbital, phenytoin, or carbamazepine may decrease blood levels of vitamin E.
  • Vitamin E use with cyclosporine appears to increase the area under the blood concentration-time curve of cyclosporine. A water-soluble form of vitamin E, tocopheryl succinate polyethylene glycol, may improve the absorption of cyclosporine (observed after liver transplantation).
  • In children, tocofersolan, a vitamin E formulation that is both fat and water soluble, has been shown to increase the availability of paclitaxel (Taxol®), vancomycin (Vancocin®), and amprenavir (Agenerase®) in the body. The formulation of amprenavir (Agenerase®) contains vitamin E at a dose of 109 IU per capsule and 46 IU per milliliter of oral solution.
  • Vitamin E may have additive effects with cholesterol-lowering medications.
  • Vitamin E has been proposed to improve the bioavailability of iron.
  • During surgery, vitamin E exhibited a protective effect against kidney problems in patients treated with the anesthetics propofol (Diprivan®) and remifentanil (Ultiva®).
  • Vitamin E may interfere with the way the body processes certain drugs using the liver's cytochrome P450 enzyme system. As a result, the levels of these drugs may be increased or decreased in the blood and may cause increased or decreased effects or potentially serious adverse reactions. Patients using any medications should check the package insert and speak with a qualified healthcare professional, including a pharmacist, about possible interactions.
  • Vitamin E may also interact with antiarthritic agents, antiasthma drugs, antituberculosis agents, aromatase inhibitors, and neurologic agents.

Interactions with Herbs and Dietary Supplements

  • High doses of oral or injected vitamin E may increase the risk of bleeding, including hemorrhagic stroke (bleeding into the brain), and caution is warranted in patients with a history of bleeding disorders or those taking herbs or supplements that may also increase the risk of bleeding. For example, multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic or saw palmetto.
  • Vitamin E may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
  • In adults not taking anticoagulants, high-dose vitamin E caused an increase in PIVKA-II (protein induced by vitamin K absence), indicating poor vitamin K status.
  • Vitamin E may have additive effects with cholesterol-lowering herbs and supplements.
  • Mineral oil may reduce dietary vitamin E absorption. The absorption of vitamin E has been shown to be influenced by the amount of fat in a meal.
  • Blood levels of vitamin E may be decreased with zinc deficiency. In patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency, vitamin E supplementation has been shown to normalize elevated copper levels and decreased zinc levels associated with the disease.
  • Increased intake of omega-6 fatty acids may increase vitamin E requirements, particularly at high doses.
  • A fish oil-enriched parenteral nutrition regimen had a positive treatment effect on serum levels of alpha-tocopherol in patients undergoing major abdominal surgery.
  • Vitamin E is involved in the absorption, storage, and utilization of vitamin A in the body and contributes to avoiding toxicity with vitamin A intake. Large doses of vitamin E may deplete vitamin A stores.
  • Aloe is reported to slow the rate of vitamin E absorption, allowing sustained release of vitamin E into the bloodstream.
  • Vitamin E has been proposed to improve the bioavailability of iron.
  • Stanyl esters have been proposed by scientists to reduce the absorption of fat-soluble vitamins. Stanyl esters dissolved in margarine did not significantly affect the absorption of alpha-tocopherol.
  • Cigarette smokers showed significant lowering of alpha-tocopherol levels in the blood. This lowering was also associated with lower levels of ascorbic acid (vitamin C) in the blood. In male smokers who have high dietary intakes of vitamin C, vitamin E supplementation was linked to an increased risk of tuberculosis.
  • Vitamin E may interfere with the way the body processes certain herbs or supplements using the liver's cytochrome P450 enzyme system. As a result, the levels of other herbs or supplements may become too high or too low in the blood. It may also alter the effects that other herbs or supplements possibly have on the P450 system.
  • Vitamin E may also interact with anesthetics, antiarthritic herbs and supplements, antiasthma herbs and supplements, anticancer herbs and supplements, anticonvulsants, antioxidants, and neurologic agents.

Categorized Under

References

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