There are many essential biological functions in which vitamin E plays a role, namely enzymatic activities, communication between cells, and the expression of various genes. Vitamin E also plays a role in neurological activities.
What is Vitamin E?
In scientific and medical terms, vitamin E actually refers to a group of eight fat-soluble molecular compounds that can broadly be separated into two groups: tocopherols and tocotrienols. The most common form in the Western diet, and that which is most biologically available for use, is γ-Tocopherol, which can be found in soybean oil, corn oil, margarine, and any food items that contain these as ingredients, such as salad dressings and marinades. α-tocopherol is the second-most abundant, and is naturally occurring in sunflower oil, wheat germ oil, and safflower oil. Vitamin E can be also be found in nuts such as walnuts and almonds. Many Vitamin E supplements can be and are artificially extracted or produced in a laboratory.
Recommended daily intake
- 0 to 6 months - 4 mg/day
- 7 to 12 months - 5 mg/day
- 1 to 3 years - 6 mg/day
- 4 to 8 years - 7 mg/day
- 9 to 13 years - 11 mg/day
- 14 and older - 15 mg/day
The primary and most recognized role of vitamin E is as an antioxidant, which is a term that is often over-used in many aspects. While antioxidants are essential to the healthy functioning of the human body, they are not miracle compounds that can be touted to "reverse" aging - this is biologically impossible and beyond the limitations of any natural compound. However, ensuring that you have a healthy and normal amount of antioxidants in your body means that you can enjoy the expectations of normal health and well-being.
As an antioxidant, vitamin E specifically acts as a scavenger of peroxyl radicals - reacting with, attaching to, and deactivating peroxyl (hydrogen peroxide based) molecules in the body. The concept of free radicals and their impact on the body stems from the Free-radical Theory of Aging, first proposed in the 1950s by Denham Harman. Free radicals are a group of naturally occurring compounds that are by-products of respiration and breathing in all living organisms. Theoretically, these oxidative free radicals increase over time, thereby giving rise to the various effects of aging that can be observed. In the 1970s, Harman refined his theory to suggest that oxidative damage occurs to the mitochondria in cells (the "powerhouses" of the cell) which might give rise to harmful mutations in DNA such as cancer and other diseases.
Theoretically, then, including antioxidants in our diet can help to eliminate free radicals and perhaps decrease the rate of damage that free radicals might be doing to our mitochondria. Since Vitamin E is fat-soluble, it can permeate through the lipid cell membranes and thereby scavenge for free radicals from inside cells.
If the free-radical theory of aging can hold its water, then antioxidants are perhaps some of the most important compounds in improving our health. We lack the medical evidence to strongly come down on one side of the issue or the other, for now, so in the meantime it is a good idea to just be informed, yet remain skeptical of any miracle claims until good evidence supports it and the medical community gets on board. Using vitamin E as a supplement might have some use as an antioxidant in the goal of slowing down oxidative damage in the body. Vitamin E might also have some other uses. Having healthy levels of vitamin E in the body means that gene expression and other metabolic functions operate on a smooth level. One clinical study found that women who had lower vitamin E intake during the second trimester had a higher risk of insulin resistance and hyperglycemia later in pregnancy.
There is much study left to be done in the world of vitamin E supplementation. As of yet, most studies surrounding vitamin E have been done using only α-tocopherol. Whilst it is one of the most common forms of the vitamin, it is just one of the eight forms the vitamin occurs in. High dosages of vitamin E can be dangerous, as can high dosage of any vitamin or supplement. If vitamin E is low in the blood, then vitamin E supplementation can be a viable option. Many credible health agencies have set the daily limit at around 1,000 mg (1,500 IU) per day.