by Caroline Johnson
The NRI’s fourth annual Virtual Internship Program (VIP) concluded on July 20 with 21 high school students from around the country presenting their research on the nutrients of their choice.
Caroline Johnson, a rising ninth grader at Pine Lake Preparatory in Mooresville, NC, concluded the Virtual Internship Program with exceptional results. Her presentation and paper were ranked in the top 3 by NRI faculty and staff. Her chosen nutrient was vitamin E. Here is Caroline’s paper.
Vitamin E is an essential micronutrient, vital to the health and well-being of many organisms. It includes different forms of fat-soluble antioxidants, known as tocopherols and tocotrienols. However, alpha-tocopherol is used by humans more than the other forms; beta, gamma, and delta (Thomas). Vitamin E is also a lipid-soluble antioxidant, meaning it scavenges free radicals and enhances the immune system.
Vitamin E was discovered in 1922 and recognized as an essential nutrient for reproduction and rat fertility. In the 1930s, scientists studied the biological function and chemical structure of this nutrient. Scientists explored the role of vitamin E as an antioxidant in the 1940s. In 1980, scientists discovered many health problems associated with free radical damage, and antioxidants came to attention (Bell).
Vitamin E has many roles in the body, including improving immune function, reducing the production of free radicals, repairing tissue, regulating genes, forming red blood vessels, and assisting the body in using vitamin K (Medline Plus).
Vitamin E also prevents many conditions in the body, including blood clots, cancer, dementia, liver disease, heart disease, stroke, hemolysis, intracranial hemorrhage, retrolental fibroplasia, inflammation, platelet aggregation, pulmonary oxygen toxicity, lung anaphylaxis, allergic disease, fetal resorption, mild cognitive impairment, and liver toxicity (Bell; Galli et al.). As a lipid-soluble antioxidant, vitamin E protects cell membranes from free radical reactions, which are harmful to tissue, organs, and cells, and play a role in aging (Thomas).
Antioxidants scavenge electrons, or free radicals, which harm cell membranes. The fats in cell membranes are susceptible to being oxidized from a free radical attack. Vitamin E, or alpha-tocopherol, breaks the chain of oxidation reactions, causing the inactivation of peroxyl radicals. In this process, vitamin E becomes oxidized and loses its antioxidant properties. However, vitamin C can restore oxidized alpha-tocopherol (Thomas). Vitamin E has an impact on the aging immune system. Alpha-tocopherol restores T Cell functions and inhibits the production of prostaglandin E2, which is a lipid mediation that suppresses T Cells (Wu et al.).
Vitamin E is initially processed enzymatically in the stomach, like fat-soluble compounds and triacylglycerols (a type of lipid), through gastric lipase (an enzyme that helps digest lipids). Then, digestion is continued by digestive enzymes secreted into the intestinal lumen. After being absorbed by the intestines, Vitamin E is bundled into chylomicrons (droplets used to transport fat), and secreted into the systemic circulation along the lymphatic pathway (Herrera and Barbas). Some of the tocopherols packaged into chylomicrons are absorbed by extrahepatic tissues, and some are transported to the liver.
The specific amounts of vitamin E needed vary from person to person. However, the recommended Dietary Allowance (RDA) meets the needs of 97% to 98% of healthy people. When there isn’t enough scientific evidence to establish an RDA, an Adequate Intake (AI) level is set at an amount believed to provide adequate nutrition (Medline Plus). Adequate vitamin E intake for infants 0-6 months is about 4 milligrams per day and 5 milligrams per day for infants 7 to 12 months old. The RDA for children 1 to 3 years old is 6 mg of vitamin E per day, and children 4 to 8 years should get 7 mg per day. 9 to 13-year-olds need 11 mg of vitamin E each day. The RDA for adults and adolescents is 15 mg daily, but lactating women need 19 mg daily (Harvard School of Public Health).
Vitamin E deficiency is extremely rare in the United States, but it may occur in people with digestive disorders or individuals who cannot absorb fat properly. Some examples of these digestive disorders include pancreatitis, cystic fibrosis, celiac disease, and other autoimmune diseases. Vitamin E deficiency can cause retinopathy, damage to peripheral nerves, ataxia, and suppressed immune function (Harvard School of Public Health).
An abundance of vitamin E can also be harmful. The highest level of vitamin E supplements that is safe for adults is 1,000 mg per day. If somebody exceeds this limit, many adverse health complications may occur. These effects include a risk of excessive bleeding due to interfering with vitamin K, hemorrhagic stroke, and an increased risk of birth defects (Medline Plus). Researchers analyzed the results of the GISSI study, the HOPE study, and other clinical trials and found that in studies where patients took over 400 IU of vitamin E supplements per day, there was a higher rate of death. However, these findings were not reliable since some of the trials were done on people with pre-existing heart conditions, and some of the studies were extremely small (Harvard School of Public Health).
Vitamin E is a necessary part of the diet and can be found in many foods, such as vegetable oils, nuts, seeds, green leafy vegetables, and other foods (Medline Plus).
Some examples of vegetable oils are sunflower, safflower, wheat germ, corn, and soybean oil. Almonds, peanuts, peanut butter, hazelnuts, and sunflower seeds are abundant in vitamin E. Some leafy vegetables that contain vitamin E are spinach, broccoli, beet greens, collard greens, and asparagus. Other vitamin E foods include pumpkin, red bell pepper, mango, avocado, fortified cereals, fruit juices, and vitamin E supplements.
There are reports of harmful effects associated with vitamin E supplements, and it is healthier to get vitamin E through the diet. However, scientists have debated whether these supplements are unsafe. Scientists combined 19 trials and found that over 400 IU of vitamin E supplements can increase the risk of death, but the results were conflicting and unreliable (Harvard School of Public Health). Altogether, obtaining vitamin E through nuts, vegetable oils, seeds, vegetables, or other foods is beneficial to the body.
In conclusion, vitamin E (alpha-tocopherol) is an essential micronutrient, and too much or too little of it can lead to negative health effects. There has been research done on the effects of vitamin E supplements, showing that taking over 400 IU of vitamin E supplements per day can lead to death, but some of the results from the studies conflicted. Alpha-tocopherol can be found in a variety of foods such as vegetable oils, nuts, seeds, and green leafy vegetables. In addition to this, vitamin E has many benefits as an antioxidant and protects cell membranes from free radicals.
VIP is a virtual summer program that provides high school students interested in nutrition with opportunities to learn from experts in the field and to complete an independent research project.
Works Cited
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Brigelius‐Flohé, Regina, and Maret G. Traber. “Vitamin E: Function and Metabolism.” The FASEB Journal, vol. 13, no. 10, July 1999, pp. 1145–55, https://doi.org/10.1096/fasebj.13.10.1145. Accessed 12 July 2023.
Galli, Francesco, et al. “Vitamin E: Emerging Aspects and New Directions.” Free Radical Biology and Medicine, vol. 102, Jan. 2017, pp. 16–36, https://doi.org/10.1016/j.freeradbiomed.2016.09.017. Accessed 11 July 2023.
Harvard School of Public Health. “Vitamin E.” The Nutrition Source, 18 Sept. 2012, www.hsph.harvard.edu/nutritionsource/vitamin-e/. Accessed 11 July 2023.
Herrera, E., and C. Barbas. “Vitamin E: Action, Metabolism and Perspectives.” Journal of Physiology and Biochemistry, vol. 57, no. 1, Mar. 2001, pp. 43–56, https://doi.org/10.1007/bf03179812. Accessed 9 July 2023.
Khadangi, Fatemeh, and Angelo Azzi. “Vitamin E – the next 100 Years.” IUBMB Life, Dec. 2018, https://doi.org/10.1002/iub.1990. Accessed 9 July 2023.
MedlinePlus. “Vitamin E: MedlinePlus Medical Encyclopedia.” Medlineplus.gov, 2019, medlineplus.gov/ency/article/002406.htm. Accessed 6 July 2023.
Niki, Etsuo, and Maret G. Traber. “A History of Vitamin E.” Annals of Nutrition and Metabolism, vol. 61, no. 3, July 2023, pp. 207–12, https://doi.org/10.1159/000343106.
Schmölz, Lisa. “Complexity of Vitamin E Metabolism.” World Journal of Biological Chemistry, vol. 7, no. 1, 2016, p. 14, https://doi.org/10.4331/wjbc.v7.i1.14. Accessed 4 July 2023.
<spThomas, Liji. “Vitamin E Alpha Tocopherol.” News-Medical.net, 29 Dec. 2009, www.news-medical.net/health/Vitamin-E-ce91-Tocopherol.aspx
Wu, Dayong, and Nikbin Meydani, Simin. “Age-Associated Changes in Immune Function: Impact of Vitamin E In…: Ingenta Connect.” Ingentaconnect.com, 2014, www.ingentaconnect.com/content/ben/emiddt/2014/00000014/00000004/art00007. Accessed 3 July 2023.
Yang, Ying, and David Julian McClements. “Vitamin E Bioaccessibility: Influence of Carrier Oil Type on Digestion and Release of Emulsified α-Tocopherol Acetate.” Food Chemistry, vol. 141, no. 1, Nov. 2013, pp. 473–81, https://doi.org/10.1016/j.foodchem.2013.03.033. Accessed 3 July 2023.
