Vitamin E is one of four fat-soluble vitamins found in the nuts, seeds and vegetable oils and nutritional supplements we consume. This vitamin is an antioxidant that helps protect cells, tissues and organs from the damaging effects of free radicals. It is also needed by the body to help keep the immune system strong. It is estimated that more than 90 percent of adults are not consuming the recommended amounts of vitamin E on a daily basis. (1) This statistic may be affecting our health, therefore it is important to identify the role of vitamin E in the body and how we can obtain adequate amounts to meet our recommended needs.
Vitamin E exists in eight different forms, each possessing varying levels of biological activity. Alpha-tocopherol is the only form of vitamin E that is actively maintained in the body and is the form found in the largest quantities in blood and tissues. (2)
Vitamin E is also an antioxidant, which means it has the ability to help slow the damaging effects of free radicals. Free radicals develop in the body during the process of metabolism, but they can also be brought on by environmental stressors like environmental pollution, cigarette smoke and ultraviolent (UV) rays from the sun. Too many free radicals in the body can damage cells. (3)
A Matter of the heart
There have been several claims about the potential use of vitamin E to promote heart health. The mechanisms by which it is thought to do so, are due to its ability to reduce inflammation, inhibit platelet aggregation and enhance immunity. (4)
In vitro studies have found that vitamin E inhibits oxidation of low-density lipoprotein cholesterol (LDL). (5) In doing so, it can stop one of the first steps of atherosclerosis (the build up of fat in arteries). (5) Additionally, research suggests that vitamin E may also help to support blood clot formation, which may contribute to heart attacks. (6)
While several observational studies have associated high levels of vitamin E intake with decreased risk of cardiovascular events, there are some studies that have casted doubt. (7) Additionally, observational studies do not prove a cause-and-effect relationship and can be subject to bias, so it is important to consider other forms of data.
Recommended dietary allowances (RDA) are established for each nutrient by the Food and Nutrition Board of National Research Council detailed as the average daily level of intake sufficient to meet the nutrient requirements of nearly all healthy people (97 – 98 percent). Current research suggests that meeting your vitamin E needs through food is preferred, but is not being achieved by the majority of the population. In this case, supplementation may be beneficial to keep vitamin E at recommended levels for optimum health.
How much is recommended
The recommended dietary allowance (RDA) of vitamin E for healthy adult is 15 milligrams per day or 22.4 international units (IU). It is important not to exceed the upper limit of vitamin E intake because it can increase the risk for hemorrhage and blood coagulation time. This value is set for 1,000 milligrams per day.
Vitamin E content of dietary supplements in typically listed in international units (IU), which is a measure of biological activity rather than quantity. One milligram of alpha-tocopherol is equivalent to 1.49 IU of the natural form or 2.22 IU of the synthetic form.
Where to find vitamin E
The best way to meet your daily requirement of vitamin E is through food. Nuts, seeds and vegetables oil are the top sources of vitamin E, particularly alpha-tocopherol the active form. This includes sunflower seeds, almonds, safflower oil and peanut butter. Vitamin E can also be found in green leafy vegetables in smaller amounts, as well as fortified foods like some breakfast cereals. Because our digestive tract requires dietary fat to absorb vitamin E, it is recommended to pair vegetables with a fat source like nuts or oil to maximize absorption.
Supplements of vitamin E typically provide alpha-tocopherol, although mixed supplement products are available. Naturally occurring alpha-tocopherol found in supplements is more biologically active than the synthetic form, which is something to keep in mind when considering supplements.