By Dr. Mercola
Vitamin E is a fat-soluble vitamin with potent antioxidant activity that helps combat damaging free radicals. It also plays a role in the making of red blood cells, helps your body use vitamin K (which is important for heart health1) and is involved in your immune function and cell signaling. As with many other nutrients, many do not get enough of this basic micronutrient from their diet.
In the U.S. alone, 75 to 90 percent of the population fails to reach the recommended dietary allowance (RDA) of vitamin E.2,3 The RDA for people over the age of 14 is 15 milligrams (mg) of vitamin E per day, but most Americans get only half that amount.4 Insufficient vitamin E can increase your risk for a wide variety of diseases, including immune dysfunction, cognitive deterioration, cardiovascular disease and certain cancers,5 especially prostate, colon and lung cancers.6,7
Obesity heightens your risk of vitamin E deficiency further, in part because the increased oxidative stress in fat cells increases your body's need for vitamin E to begin with. Obesity also impairs your body's utilization of vitamin E.8,9 Food is your best source of vitamin E, since food contain a combination of the eight types of vitamin E. If you're using a supplement, there are key considerations that need to be heeded, which I'll review below.
Low Vitamin E Level Again Linked to Higher Risk of Colorectal Cancer
A number of studies have looked at vitamin E's influence on diseases like cancer. It's important to realize that while some studies have linked vitamin E supplementation to an increased risk for cancer,10 most of those studies were looking at synthetic vitamin E, which I do not recommend using. Natural vitamin E, on the other hand, has a protective effect. Studies assessing the anti-cancer potential of natural vitamin E found that:
- 300 IUs11 of natural vitamin E per day may reduce lung cancer risk by 61 percent12
- Gamma-tocotrienol, a cofactor found in natural vitamin E preparations, may decrease prostate tumor formation by 75 percent13
- Gamma-tocotrienol also fights existing prostate cancer tumors and may inhibit growth in human breast cancer cells14
Most recently, a meta-analysis15 of 11 studies concluded that patients with lower concentrations of serum vitamin E (the vitamin E level in your blood) had a higher risk for colorectal cancer. A much earlier study,16 published in 1993, also found that high intake of vitamin E helped decrease the risk of colorectal cancer — especially in those under the age of 65. As explained in the study:
"Vitamin E is the major lipid-soluble antioxidant found in cell membranes, where it protects against lipid peroxidation. In addition, like carotenoids and water-soluble vitamin C, it can also stimulate the immune system and may protect against the development of cancer by enhancing immune surveillance. Vitamins E and C reduce nitrite, compounds that induce tumors …"
Other Health Benefits of Natural Vitamin E
Aside from its cancer-preventive potential, natural vitamin E may also:
• Lower your risk of heart disease and stroke17
• Help relieve symptoms associated with nonalcoholic steatohepatitis, a common obesity-related fatty liver disease
• Lower your risk of age-related macular degeneration, a leading cause of vision loss in the elderly18
• Boost improvements in blood vessel function that occur when a smoker quits smoking19
• Delay loss of cognitive function in Alzheimer's patients.20 Results showed that clinical progression of Alzheimer's slowed by 19 percent per year in the group receiving 2,000 IUs per day of vitamin E, compared with placebo. This delay translated into just over six months of delayed progression over the two-year follow-up period. Caregiver time also increased the least in the group receiving vitamin E.
This study actually used synthetic alpha-tocopherol that was not balanced with tocotrienols or any of the other tocopherols — beta, gamma and delta. Chances are the benefits would have been even greater if the natural form was used
How Much Vitamin E Do You Need for Optimal Health?
According to one scientific review,21,22 a mere 21 percent of the people studied had a protective level of serum vitamin E, which is thought to be 30 micromol per liter (μmol/L). This appears to be the threshold above which "definable effects on human health in multiple areas" are obtained.23 Human studies have also found that achieving a level of 30 μmol/L requires a daily intake of at least 50 IUs of vitamin E.24
A primary reason for such widespread deficiency is that most people eat a primarily processed food diet, which tends to be lacking in vitamin E and other important nutrients. Moreover, following a low-fat diet can have the undesirable side effect of lowering your vitamin E level, as your ability to absorb the vitamin E present in the foods you eat or supplements you take is then impaired.
Since vitamin E is fat-soluble, taking it with some healthy fat, such as coconut oil or avocado, can help increase its bioavailability. In fact, studies have shown your body will absorb only about 10 percent of the vitamin E from a supplement when you take it without fat.25
Signs and Symptoms of Vitamin E Deficiency and Why Vitamin E Is so Important During Pregnancy
Signs and symptoms of serious vitamin E deficiency include:26,27
Muscle weakness and unsteady gait
Loss of muscle mass
Vision problems, including constriction of your visual field; abnormal eye movements; blindness
Liver and kidney problems
Deficiency during pregnancy can be particularly problematic. Worldwide, about 13 percent of people have vitamin E levels below the "functional deficiency" threshold of 12 μmol/L, and most of these are newborns and young children. Babies deficient in vitamin E are at increased risk for immune and vision problems. Being deficient in vitamin E during pregnancy also raises your risk for miscarriage.28
Natural Versus Synthetic Vitamin E
Synthetic vitamin E is derived from petrochemicals and has known toxic effects, yet synthetic alpha-tocopherol is the type most commonly used when investigating the health effects of vitamin E. Hence, it's not so surprising that synthetic vitamin E supplements would fail to provide certain health benefits and potentially increase certain health risks.
Natural vitamin E includes a total of eight different compounds, and having a balance of all eight helps optimize its antioxidant functions. These compounds are divided into two groups of molecules as follows:
Tocopherols are considered the "true" vitamin E, and many claim it's the only kind that has health benefits. Part of the problem with tocotrienols is that they simply haven't received as much scientific attention. In my view, it's safe to assume you would benefit from a balance of all eight and not just one. Foods are the ideal source of vitamin E, as all eight vitamin E compounds are naturally available.
Synthetic vitamin E supplements typically include only alpha-tocopherol, and research29,30 published in 2012 concluded that synthetic alpha tocopherols found in vitamin E supplements provided no discernible cancer protection while gamma and delta tocopherols found in foods do help prevent colon, lung, breast and prostate cancers. Bear in mind that a supplement will not actually tell you it's synthetic, so you have to know what to look for on the label.
- Synthetic alpha-tocopherol is typically listed with a "dl" (i.e., dl-alpha-tocopherol)
- Nonsynthetic or naturally-derived is typically listed with a "d" (d-alpha-tocopherol)
Note that when vitamin E is stabilized by adding either succinic acid or acetic acid, the chemical name changes from tocopherol to tocopheryl (as in d-alpha-tocopheryl succinate, for example).
Guidance When Choosing a Vitamin E Supplement
I strongly recommend avoiding synthetic vitamin E supplements as they've been shown to have toxic effects in higher amounts and/or over the long term. Synthetic vitamin E has also been linked to an increased tumor progression and accelerated lung cancer in mice.31 So, if you opt for a supplement, make sure you're getting a well-balanced all-natural vitamin E supplement, not a synthetic one.
Another potential problem is that if you take high amounts of alpha-tocopherol in isolation, it could potentially deplete the other tocopherols and tocotrienols from your body. This is true whether you're taking a natural or a synthetic one, so I recommend looking for a food-based supplement that has a balance of all eight types of vitamin E (four tocopherols and four tocotrienols).
Also look for a supplement that is free of soy, soybean oil derivatives and genetically engineered (GE) ingredients (some of the most common GE ingredients found in supplements are derivatives of corn, soy and cotton seed).
Your Best Source of Vitamin E
Supplements are best taken in addition to, not in place of, a healthy diet, and only if you actually need them. One way to evaluate your need for a vitamin E or other supplements is to use a nutrient tracker, such as Cronometer.com/Mercola, which is the most accurate one on the market because of their decision to eliminate inaccurate crowd sourced data. It's available free of charge.
Vitamin E can easily be obtained from a healthy diet, so before considering a supplement, consider including more vitamin E-rich foods in your diet. Vitamin E is synthesized by plants, and the highest amounts are found in plant oils.
However, while some health authorities recommend canola oil as a good source,32 this is actually a terrible source. Beans — which are a good source of vitamin E — may also be problematic for many due to their high lectin content. Three general categories of foods that contain higher amounts of vitamin E that will circumvent these potentially problematic sources are:
- Leafy greens
- High-fat foods such as nuts, seeds and fatty fish/seafood, including shrimps and sardines
- Oil-rich/high-fat plants such as olives and avocados
More specific examples of foods high in vitamin E include:33,34
|Food||Serving Size||Vitamin E (mg)|
|1 ounce||6.8 to 7.3 mg|
|1 tablespoon||5.6 mg|
|1 ounce||4.3 mg|
|1 cup||3.2 mg|
|1/2 cup||1.2 mg|
|1/2 cup||0.7 mg|
|1 cup||0.6 to 3.8 mg|
|1 cup||2.7 mg|