Vitamin E is a fat-soluble antioxidant in many foods. It supports the immune system, helps keep blood vessels healthy, and plays a role in gene expression and cell signaling.
There are eight forms of naturally occurring vitamin E, and alpha-tocopherol is the one that the body mainly uses.
In this article, we explore evidence of specific health benefits of vitamin E. We also look at food sources and supplements, including interactions and other risks.
How vitamin E may help
Vitamin E acts as an antioxidant — it helps protect the body from free radicals.
Free radicals are molecules generated as a normal part of metabolism. They can cause damage and disease and contribute to the aging process.
Additionally, vitamin E is important for immune function, gene expression, and cell signaling. It helps widen blood vessels and prevent excessive clotting.
Researchers have investigated whether vitamin E may also help prevent or treat specific conditions.
The results concerning many uses of the vitamin, including to help prevent cognitive decline, are conflicting or inconclusive.
Despite a general lack of strong conclusions, the National Institutes of Health (NIH) cite some research suggesting that vitamin E might have particular benefits for people with:
Coronary heart disease
Various studies suggest that vitamin E can help prevent or delay coronary heart disease (CHD).
In vitro research indicates that vitamin E inhibits the formation of low-density lipoprotein cholesterol and may thus help prevent blood clots. In addition, several observational studies associate lower rates of heart disease with higher vitamin E intakes.
However, some randomized clinical trials cast doubt on the ability of vitamin E supplements to help prevent CHD.
Overall, the NIH observe, determining whether vitamin E supplements benefit people with CHD will require more extended studies that include younger participants.
Vitamin E may help prevent age-related macular degeneration.
The NIH cite evidence that taking vitamin E with zinc, copper, and other antioxidants may slow the disease’s progression in people with a high risk of an advanced form.
However, they acknowledge that the evidence supporting the use of vitamin E to treat or prevent eye disorders is inconsistent.
Researchers have investigated the antioxidant and immune-modulating effects of vitamin E on cancer. For example, an older study, from 2002, found that long-term vitamin E supplementation may reduce death from bladder cancer.
However, the NIH warn that there is currently not enough evidence to support taking vitamin E for cancer. They also report that it may increase the risk of prostate cancer.
The Selenium and Vitamin E Cancer Prevention Trial found that males taking vitamin E had an increased risk of prostate cancer, but that participants who also took supplements of the trace mineral selenium did not have an increased risk.
Overall, a person should not take vitamin E or selenium supplements for cancer prevention, as researchers do not fully understand how these supplements work.
They are also unsure whether these supplements interact with foods, other supplements, and medicines.
The safety of vitamin E supplements
The NIH warn of health risks associated with vitamin E supplements.
They cite research linking using high-dose vitamin E supplements to increased risk of hemorrhagic stroke, which results from bleeding in the brain, and prostate cancer.
They also report that vitamin E supplements may increase the risk of bleeding in people taking anticoagulant drugs such as warfarin (Coumadin).
In addition, the NIH warn that vitamin E supplements can interact with a combination of simvastatin and niacin, as well as with chemotherapy and radiotherapy.
Pregnancy and breastfeeding
Authors of a 2015 review found that the available research does not support taking vitamin E supplements during pregnancy.
The nutrient does not help prevent pregnancy problems and may cause abdominal pain and early rupture of membranes, the team reports.
Research into vitamin E and lactation is scarce. Overall, anyone who is breastfeeding should speak with a healthcare professional before taking any supplements.
Where to find vitamin E
Vitamin E is in many foods and also available as a supplement.
Foods rich in vitamin E
A person can find vitamin E in:
seeds, such as sunflower or pumpkin seeds
vegetable oils, such as wheat germ, sunflower, or safflower oil
nuts, including almonds, hazelnuts, and walnuts
green vegetables, such as spinach, collard greens, and broccoli
red bell peppers
many fortified foods, such as cereals, fruit juices, and margarine
Below, learn how much vitamin E is in specific foods:
Vitamin E supplements are available in natural or synthetic forms.
The NIH note that manufacturers usually label natural forms with the letter “d,” as in “d-gamma-tocopherol.” They label synthetic forms “dl,” as in “dl-alpha-tocopherol.”
The Food and Drug Administration (FDA) have required manufacturers to list vitamin E quantities in milligrams (mg) since January 2020. Smaller companies may still use old labels listing the contents in international units (IU) until January 2021.
People can convert IU to mg using the following formulae:
1 IU of the natural form is equivalent to 0.67 mg of alpha-tocopherol.
1 IU of the synthetic form is equivalent to 0.45 mg of alpha-tocopherol.
People can convert mg to IU with the following formulae:
1 mg of the natural form of alpha-tocopherol is 1.49 IU.
1 mg of the synthetic form of alpha-tocopherol is 2.22 IU.
How much per day?
The recommended daily allowance, or RDA, of vitamin E varies, depending on a person’s age and breastfeeding status:
Vitamin E is an important antioxidant nutrient that supports the immune system and the health of the blood and blood vessels. It is also involved in gene expression and cell signaling.
People usually get enough vitamin E from a healthful diet that contains adequate fats. Vitamin E-rich foods include nuts, seeds, and vegetable oils. However, health issues that affect the absorption of nutrients may cause a person to develop a deficiency.
Research into the capacity of vitamin E to prevent or treat specific health issues is generally conflicting. However, further studies may confirm suggested benefits for people with heart disease or age-related macular degeneration.
Anyone taking ongoing medication should check with a doctor before taking vitamin E supplements. Consulting an oncologist first is crucial for people who have cancer, especially if they are currently undergoing treatment.
What are the symptoms of low vitamin E?
The body needs vitamin E to function, making it an essential vitamin. It is fat-soluble, meaning that it requires fat from the diet to be properly absorbed. Vitamin E is mainly stored in the liver before being released into the blood stream for use.
Deficiency is uncommon and typically the result of an underlying condition. Some premature infants also have low levels.
Vitamin E occurs in eight chemical forms. With a blood test, a doctor can learn how much of one form, alpha-tocopherol, a person has. Using this information, they can determine whether a person’s overall level of vitamin E.
A normal level is usually with the range of 5.5–17 milligrams per liter (mg/L). The normal range may be different for premature infants and children under 17. Normal ranges can also vary slightly among labs.
When an adult has less than 4 mg/L of vitamin E in their blood, they usually require supplementation.
Signs and symptoms of deficiency
Low levels of vitamin E can lead to:
Muscle weakness: Vitamin E is essential to the central nervous system. It is among the body’s main antioxidants, and a deficiency results in oxidative stress, which can lead to muscle weakness.
Coordination and walking difficulties: A deficiency can cause certain neurons, called the Purkinje neurons, to break down, harming their ability to transmit signals.
Numbness and tingling: Damage to nerve fibers can prevent the nerves from transmitting signals correctly, resulting in these sensations, which are also called peripheral neuropathy.
Vision deterioration: A vitamin E deficiency can weaken light receptors in the retina and other cells in the eye. This can lead to loss of vision over time.
Immune system problems: Some research suggests that a lack of vitamin E can inhibit the immune cells. Older adults may be particularly at risk.
Muscle weakness and difficulties with coordination are neurological symptoms that indicate damage to the central and peripheral nervous systems.
The peripheral system is the network of nerves located beyond the brain and spinal cord. These neurons pass messages throughout the body.
The central nervous system communicates between the brain and the spinal cord.
The sheaths of neurons are mostly composed of fats. When the body has too little vitamin E, it contains fewer antioxidants that protect these fats, and the function of the nervous system breaks down.
Causes of vitamin E deficiency
Vitamin E deficiency often runs in families.
Learning about family history can make diagnosing certain rare, inherited diseases easier. Two of these diseases, congenital abetalipoproteinemia and familial isolated vitamin E deficiency, are chronic and result in extremely low vitamin E levels.
Vitamin E deficiency can also result from diseases that severely reduce the absorption of fat. This is because the body requires fat to absorb vitamin E correctly.
Some of these diseases include:
cholestatic liver disease
Deficiency is also common in newborns and babies born prematurely who have lower birth weights and less fat.
Premature infants are at particular risk because an immature digestive tract can interfere with fat and vitamin E absorption.
Vitamin E deficiencies in these infants can also lead to hemolytic anemia, which destroys red blood cells.
When to see a doctor
When a person has no history of genetic disease but experiences any symptoms of a vitamin E deficiency, they should contact a doctor.
An extremely low level of vitamin E in the blood can indicate an underlying health issue. Further testing will help to determine the cause and treatment options.
What are the treatment options?
Vitamin E supplementation is often effective.
Newborns and premature babies
Current practice involves providing vitamin E supplementation through a tube in the stomach. When necessary, it can also be administered intravenously.
While one dose can sufficiently raise blood levels of vitamin E, multiple doses may be required.
Children and adults
Children and adults with deficiencies caused by inherited conditions require supplementation with high doses of vitamin E.
Supplementation can stop the progression of the disease. When the deficiency is detected early, it may prevent neurological symptoms.
Vitamin E in the diet
It is highly unlikely that a person has low levels of vitamin E unless they have an underlying chronic disease, a genetic condition, or a diet extremely low in fat. For others, supplementation is usually not necessary.
Vitamin E is plentiful in a wide variety of foods. The body cannot produce it, so it must be obtained from the diet or a supplement.
Foods that contain vitamin E include:
vegetable oils, such as wheat-germ oil, peanut oil, and olive oil
most vegetables, including spinach, Swiss chard, red peppers, and avocados
A person should not take too many supplements of fat-soluble vitamins, including vitamins A, D, E, and K.
Excessive levels of vitamin E may cause abnormal bleeding, muscle aches, diarrhea, and vomiting. The bleeding can increase the risk of a stroke and early death.
Too much vitamin E can also interact with blood thinners, such as warfarin, and chemotherapy medications.
A person should inform the doctor of all supplements and vitamins they take regularly. Do not exceed the recommended dosage of supplements unless instructed to by a physician.
When an adult has a vitamin E deficiency, a chronic illness or genetic condition is likely responsible.
A person should seek treatment from a specialist and a qualified dietitian who has experience with the illness.
When a diet extremely low in fat is responsible for the deficiency, it can be remedied by adding fats to the diet.
Ongoing vitamin E supplementation will be necessary to halt the progression of illness and prevent complications. When a person is diagnosed early and receives continuous treatment, their outlook is usually good.
Research continues on vitamin E supplementation, toxicity, and safe limits.