Vitamin E (Tocopherols / Tocotrienols)

What is Vitamin E?

Vitamin E is a fat-soluble vitamin and refers to a group of eight compounds in tocopherol and tocotrienol forms. The compounds are alpha-, beta-, gamma- and delta-tocopherol and alpha-, beta-, gamma- and delta-tocotrienol. Of the eight compounds alpha-tocopherol is the only compound needed to meet dietary requirements. Alpha-tocopherol form of vitamin E is the most biologically active form.

The word tocopherol comes from the Greek word ‘Tokos’ which means ‘offspring’ or ‘child birth’. ‘Phero’ means to ‘bring forth’. The ‘ol’ part of the word refers to alcohol. Vitamin E is natural made in many plants and available in plant food sources. It is found in many different vegetable oils. Vitamin E has been found to be important for reproduction in rats which is how it was initially discovered.

Vitamin E is excreted from the body through feces and bile. Vitamin E acts as an antioxidant helping to eliminate free radicals. Vitamin E is absorbed in the small intestines with alpha-tocopherol metabolized in the liver and is stored in the liver, muscles and fat (adipose tissue). Other forms of vitamin E are excreted by the liver. Up to 25% of vitamin E is absorbed when taken orally. [1] [2] [3] [4]

Health benefits of Vitamin E

Supports blood cells and health of blood vessels

Vitamin E is involved in the formation of red blood cells. It works synergistically with vitamin K by helping to utilise K in the body and prevent blood from clotting inside the blood vessels. Vitamin E also has vasodilating effects. This may help to reduce the risk of atherosclerosis and heart disease. Vitamin E also has blood-thinning effects which may be helpful in those at risk of heart disease.

Supports thyroid health

Vitamin E helps with selenium metabolism. Selenium is needed to process thyroid hormones and works synergistically with vitamin E. Taking excessive vitamin E supplements may reduce selenium levels and potentially cause certain thyroid disorders. [5] [6]

Supports immune system

Vitamin E has antioxidant properties that can help support the immune system. Vitamin E helps support the immune system against viruses and bacteria and works synergistically with other antioxidant nutrients. In addition to vitamin E other key nutrients have also shown some benefits on the immune system which includes vitamin C. [7] [8] [9]

Helps heal wounds

Vitamin E has an important function in the healing process of wounds with its antioxidant activity and helps maintain and protect the health of cells. It protects cells from oxidation and free radicals. It works synergistically with vitamin C in its role of reducing free radicals in the body and both are key nutrients for antioxidant activity. [10]

Prevents free radical damage

Damage of cells from free radicals which contribute to oxidation can lead to a number of health conditions such as cardiovascular disease, cancer, premature aging, dementia, stroke and Alzheimer's disease although more research is required. Vitamin E acts as a free radical scavenger and prevent oxidative damage by free radicals. It also protects oxidative damage in lipid molecules such as polyunsaturated fatty acids (PUFAs) and LDL cholesterol.

Vitamin E works synergistically with other nutrients that have antioxidant properties such as vitamin A, C and selenium. [11] [12]

Agonist / Synergist

Vitamins: A, B1, B2, B3, B5 B6, B9, B10, B12, C, D, E (compounds), K

Minerals: Ca, Fe, K, Mn, Na, P, Se, Zn

Other: Bile, fats

Bile is needed for absorption of vitamin E.

Fat helps with vitamin E absorption.

Vitamin E increases vitamin A absorption [13]

Vitamin A and E work synergistically and have antioxidant properties.

Vitamin E helps the body utilize vitamin K.

Vitamin C, vitamin E and selenium are antioxidants that work synergistically for maintaining health and deficiency or imbalance of each can directly impact use of each nutrient in the body. [14]

Vitamin C and E work synergistically and function as antioxidants however high dose of vitamin C may increase requirement for vitamin E. High doses of vitamin E can also increase the requirement of vitamin C. [15] [16]

Vitamin C helps protect vitamin E by helping to recycle it into the active form of E.

Vitamin E can reduce harmful effects of selenium toxicity.

Selenium and vitamin E induce apoptosis. [17] [18]

Vitamin E and selenium work synergistically to help reduce effects of iron overload. [19]

Vitamin E helps increase manganese absorption.

Vitamin E helps increase zinc absorption.

A combination of the eight compounds of vitamin E which includes alpha-, beta-, gamma- and delta-tocopherol and alpha-, beta-, gamma- and delta-tocotrienol will work synergistically as opposed to using only d-alpha-tocopherol compound.

Vitamin E can increase sodium levels, this could be of benefit in certain health conditions where sodium levels are low however needs to be avoided if sodium intake is already high or there are existing health conditions which can get worse such as high blood pressure (hypertension).

Antagonists

Vitamins: A, C, D, E (in excess amounts), K

Minerals: Ca, Fe, Mg, Mn, Zn

Vitamin A can reduce absorption of vitamin E. [20]

Vitamin D can reduce absorption of vitamin E. [21]

High doses of vitamin K reduces vitamin E absorption. [22]

Iron can reduce absorption of vitamin E.

Vitamin E inhibits iron uptake.

Vitamin E deficiency can worsen effects of iron overload which may be corrected with vitamin E supplements. [23]

Excessive vitamin E intake can increase risk of heart disease. An excess may also lower vitamin C levels which has also been associated with the risk of heart disease.

Prolonged excessive use of vitamin E may reduce calcium.

Prolonged excessive use of vitamin E may reduce vitamin K.

Excessive vitamin E may reduce vitamin A levels.

Vitamin E may inhibit absorption vitamin A.

Vitamin E may inhibit absorption vitamin K.

Vitamin E can reduce calcium levels.

Food sources of Vitamin E

Common foods containing vitamin E include foods obtained from plant sources. Food sources of vitamin E include nuts (peanuts, almonds, hazelnuts), nut butters, seeds, milk fat, egg yolk, green leafy vegetables (spinach, broccoli, asparagus, turnip greens), fish, wheat germ, avocado,

Vitamin E can be found in vegetable oils which include sunflower oil, safflower oil, wheat germ oil, corn oil, and soybean oil. Some foods are also fortified in foods such as breakfast cereals, fruit juices, margarines and spreads. Margarines should be avoided due to trans fats.

Recommended Dietary Allowance

The amounts recommended for vitamins and minerals are different for each country which can be found on the government website of host country. The nutritional data for each country are based on scientific research which are presented by the scientific academies in each country to help advise governmental departments for food and human nutrition.

Below is a list of some of the countries and the EU for which nutritional guidelines are available found on corresponding official government website (including the national academy of science website for the USA).

Vitamin E Supplementation

Vitamin E compound alpha-tocopherol is available in natural and synthetic form. It is found mostly as softgel capsules in combination with sunflower oil. The natural form is labelled as d-alpha-tocopherol and the synthetic form of vitamin E is labelled as dl-a-tocopherol acetate and is mostly derived from petroleum products. The natural form is the best form of vitamin E as it is better absorbed and less is required in comparison to synthetic vitamin E.

Vitamin E is a fat-soluble vitamin and low dosage supplement may be better as the vitamin can be stored in fat, liver and muscle.

Deficiency symptoms of Vitamin E

Signs and symptoms of vitamin E deficiency include:
Oxidative stress
Disorientation
Neurological problems
Vision problems (Retinopathy e.g a narrow field of vision or blindness)
Speech problems (dysarthria)
Nerve and muscle damage
Ataxia
- Problems with walking and coordination
- Loss of body movement and control
- Balance problems
Muscle weakness (skeletal myopathy)
Loss of feeling in the arms and legs (peripheral neuropathy)
Dementia
Positive Babinski sign*
Muscle pain
Loss of muscle mass
Irregular heartbeat
Liver problems
Kidney problems
Fatigue
Red blood cells splitting which can cause anemia (Erythrocyte hemolysis)
Anemia (Hemolytic)
Impairment of the immune response
Skin problems
Hair loss

Positive Babinski sign is demonstrated with the big toe bending upwards with the remaining toes fanning outwards.

Deficiency of vitamin E in developed countries are uncommon however it may occur from the following causes:

Inadequate intake
Fat malabsorption(due to coeliac disease, cystic fibrosis, pancreatitis or Crohns disease)
Malnutrition (in those with chronic conditions such as cancer)
Liver disease (bile duct obstruction or primary biliary cirrhosis)
Poor diet
Alcoholism (damages liver function)

Premature infants are affected by vitamin E deficiency as transfer of vitamin E from mother to baby is impeded.

A study on guinea pigs has shown that both a selenium and vitamin E deficiency can result in fatal myopathy. [26]

Toxicity symptoms of Vitamin E

Toxicity of vitamin E can occur from taking excessive vitamin E supplements. No toxicity has been found from dietary intake of vitamin E. The following are some signs and symptoms of vitamin E toxicity:

Fatigue
Muscle weakness
Nausea
Diarrhea
Prevent blood coagulation
Bleeding* (haemorrhage)
Increased risk of stroke (hemorrhagic)
Premature death
Inhibited platelet aggregation
Reduce selenium levels
Reduce vitamin A levels
Reduce vitamin K levels
Reduce calcium levels
May increase risk of prostate cancer

*Risk of bleeding is likely if taking extremely high doses of more than the upper limit of 1000mg per day or if taking warfarin (Coumarin).

Some studies have shown an increased risk of death and heart failure at doses of 400 IU per day in those with diabetes or cardiovascular disease.

Study on men has shown those taking a multivitamin in addition to supplementation of vitamin E more than seven times per week have an increased risk of prostate cancer.

Vitamin E has also shown to cause congenital heart defects in pregnant women who take the supplement in the first eight weeks of pregnancy.

Precautions and warnings

Vitamin E may interact with certain medications such as warfarin. It is important to seek medical guidance from a health physician before supplementing with vitamin E.