Vitamin E is a fat-soluble vitamin that acts as a powerful antioxidant in the body, protecting cells from damage caused by free radicals. It is essential for maintaining good health and plays a role in immune function, gene expression, and other metabolic processes. There are eight different forms of vitamin E, including four tocopherols (alpha, beta, gamma, and delta) and four tocotrienols (alpha, beta, gamma, and delta). Alpha-tocopherol is the most biologically active and well-studied form of vitamin E.
The discovery of vitamin E dates back to the early 20th century. In 1922, researchers Herbert McLean Evans and Katherine Scott Bishop conducted experiments on rats at the University of California, Berkeley. They found that rats fed a diet lacking in a specific fat-soluble factor exhibited fertility problems. This factor, initially called “Factor X,” was later named vitamin E.
In 1936, Evans and his colleagues successfully isolated vitamin E from wheat germ oil, and by 1938, the chemical structure of alpha-tocopherol was identified by Paul Karrer and his team. The synthesis of vitamin E was achieved by a group of researchers led by Karrer in 1938.
Subsequent research on vitamin E revealed its role as a potent antioxidant, protecting cells from damage caused by free radicals, which are reactive molecules generated by normal metabolic processes and external factors like pollution and radiation. In addition to its antioxidant properties, vitamin E has been found to play a role in immune function, gene expression, and other physiological processes.
Functions Of Vitamin E
Vitamin E is a fat-soluble antioxidant that plays several vital roles in maintaining overall health and supporting various physiological processes. Some of the primary functions of vitamin E include:
- Antioxidant activity: Vitamin E acts as a potent antioxidant, neutralising free radicals and protecting cells from oxidative damage. This helps maintain the integrity of cell membranes and reduce the risk of chronic diseases related to oxidative stress, such as cardiovascular disease and certain types of cancer.
- Immune system support: Vitamin E plays a role in supporting immune function by enhancing the activity of immune cells like T cells, B cells, and natural killer cells. This helps protect the body against infections and illnesses.
- Anti-inflammatory properties: Vitamin E has been shown to possess anti-inflammatory properties, which can help reduce inflammation in the body and potentially lower the risk of chronic inflammatory diseases.
- Gene expression: Vitamin E is involved in the regulation of gene expression, influencing the expression of genes related to cell growth, differentiation, and metabolism.
- Neurological function: Vitamin E is essential for maintaining healthy nervous system function, and deficiencies can lead to neurological disorders. Some studies suggest that adequate vitamin E intake may help prevent or slow the progression of age-related cognitive decline and neurodegenerative diseases like Alzheimer’s disease, although more research is needed in this area.
- Cardiovascular health: Vitamin E may have a protective effect on cardiovascular health by preventing the oxidation of low-density lipoprotein (LDL) cholesterol, which can contribute to atherosclerosis, a primary risk factor for heart disease.
- Skin health: Vitamin E contributes to skin health by providing antioxidant protection against environmental factors like UV radiation, pollution, and other sources of oxidative stress that can cause skin damage and premature aging.
Good Sources Of Vitamin E
Vitamin E is found naturally in a variety of foods, particularly in plant-based sources. Some good sources of vitamin E include:
- Vegetable oils: Vitamin E is abundant in many vegetable oils, such as wheat germ oil, sunflower oil, safflower oil, and corn oil. Wheat germ oil is considered one of the richest sources of vitamin E.
- Nuts: Almonds, hazelnuts, and peanuts are good sources of vitamin E. Almonds, in particular, are an excellent choice, providing a substantial amount of vitamin E in a small serving.
- Seeds: Sunflower seeds, pumpkin seeds, and sesame seeds are rich in vitamin E, making them a nutritious and tasty addition to meals and snacks.
- Green leafy vegetables: Spinach, Swiss chard, collard greens, and kale contain moderate amounts of vitamin E. Consuming a variety of these vegetables regularly can help increase your vitamin E intake.
- Fruits: Some fruits, such as kiwi, mango, and avocado, provide modest amounts of vitamin E. Incorporating these fruits into your diet can contribute to meeting your daily vitamin E needs.
- Fortified cereals: Some breakfast cereals and other grain products are fortified with vitamin E, making them a convenient source of this nutrient.
- Fish: Although not as rich in vitamin E as plant-based sources, certain fatty fish like salmon, rainbow trout, and mackerel contain small amounts of vitamin E.
- Eggs: Eggs, particularly the yolks, provide a modest amount of vitamin E, contributing to a balanced diet.
How Much Vitamin E Do We Need?
According to the NIH, the Recommended Dietary Allowance (RDA) for vitamin E is based on age and sex:
- Infants (0-6 months)*: 4 mg/day (milligram)
- Infants (7-12 months)*: 5 mg/day
- Children (1-3 years): 6 mg/day
- Children (4-8 years): 7 mg/day
- Children (9-13 years): 11 mg/day
- Adolescents (14-18 years): 15 mg/day
- Adults (19 years and older): 15 mg/day
- Pregnant women (all ages): 15 mg/day
- Breastfeeding women (all ages): 19 mg/day
*For infants, the values provided are Adequate Intakes (AI) rather than DRIs, as there is not enough data to establish DRIs for this age group.
These values are general guidelines, and individual needs may vary depending on factors such as overall health, lifestyle, and diet. It is essential to consume adequate amounts of vitamin E through a balanced diet that includes a variety of vitamin E-rich foods. If you are concerned about your vitamin E intake or have specific health concerns, consult with a healthcare professional for personalised advice.
What Are The Sign Of Vitamin E Deficiency?
Vitamin E deficiency is relatively rare in healthy individuals, as the vitamin is widely available in various foods, and the body can store it in fat tissue. However, certain conditions or genetic disorders can lead to vitamin E deficiency. Some of the signs and symptoms of vitamin E deficiency include:
- Neuromuscular problems: Deficiency in vitamin E can cause damage to nerve cells, resulting in impaired muscle coordination, muscle weakness, and difficulty walking. This is often seen in conditions like spinocerebellar ataxia or peripheral neuropathy.
- Sensory issues: Vitamin E deficiency can lead to sensory problems such as impaired vibratory sensation and position sense, making it difficult to sense the position of one’s limbs.
- Vision problems: Vitamin E deficiency can result in retinopathy, affecting the eyes and leading to vision problems, including difficulty seeing at night and slow adjustment to changes in light levels.
- Immune system dysfunction: Low vitamin E levels can weaken the immune system, making individuals more susceptible to infections and illnesses.
- Haemolytic anaemia: In rare cases, vitamin E deficiency can cause haemolytic anaemia, a condition where red blood cells break down prematurely, leading to fatigue, weakness, and shortness of breath.
- Reproductive issues: Although rare, severe vitamin E deficiency has been linked to reproductive problems, such as infertility and miscarriages.
It is important to note that vitamin E deficiency is more likely to occur in individuals with fat malabsorption disorders (e.g., cystic fibrosis, Crohn’s disease), premature infants with low birth weight, and individuals with rare genetic disorders affecting vitamin E metabolism. If you suspect a vitamin E deficiency, consult with a healthcare professional for proper diagnosis and treatment.
What Happens If I Take Too Much Vitamin E?
Vitamin E is a fat-soluble vitamin, which means that excess amounts can be stored in the body’s fatty tissues. While it is rare to experience toxicity from vitamin E obtained through food sources alone, taking high doses of vitamin E supplements can potentially lead to adverse effects. Some of the symptoms and consequences of excessive vitamin E intake include:
- Increased risk of bleeding: High doses of vitamin E can interfere with blood clotting, increasing the risk of bleeding, particularly in individuals taking blood-thinning medications like warfarin or those with vitamin K deficiency.
- Nausea and diarrhoea: Excessive vitamin E intake can cause gastrointestinal symptoms such as nausea, diarrhoea, and stomach cramps.
- Fatigue and weakness: Overconsumption of vitamin E supplements may lead to general feelings of fatigue and muscle weakness.
- Blurred vision: In some cases, excessive vitamin E intake may cause blurred vision or other vision-related issues.
- Headaches: High doses of vitamin E can sometimes result in headaches.
- Hormonal imbalances: Some studies suggest that excessive vitamin E intake might interfere with the balance of thyroid hormones, although more research is needed to confirm this.
- Reduced bone mineral density: There is some evidence that extremely high doses of vitamin E can negatively affect bone mineral density, potentially increasing the risk of fractures.
- Increased risk of certain health conditions: Some studies have suggested that high doses of vitamin E might be associated with an increased risk of prostate cancer in men, heart failure, and haemorrhagic stroke, although more research is needed to establish a clear link.