WHILE the important role of vitamin E as a lipid-soluble antioxidant vitamin has been well established, little attention has been given to the potential for inadequacy among college-age individuals. Furthermore, vitamin E has had its reputation somewhat “tarnished,” ever since a 2005 meta-analysis reported increased mortality with supplemental use longer than a year.1 Sales of vitamin E supplements fell following this report.2 The Harvard Heart Letter lamented, “Oh E, how could you do this to us?” and “It's time to let E go.”3 This newsletter recommended a return to whole food sources of vitamin E, but this message seemed to be lost under the more attention-grabbing warning of potential harm.
While high-dose supplements were later determined to have no effect on all-cause mortality,4 this updated information may not have been enough to counteract the negativity surrounding vitamin E. This perception may also have affected an appreciation for the need to ensure “normal” amounts of vitamin E from daily food sources. However, vitamin E is essential for preventing free radical damage throughout the body, including the all-important brain and nervous system.5
Dietary vitamin E intake among people of all ages is insufficient, and, in particular, among young adults in their formative years.6 , 7 A study of healthy college students revealed that 41% of men and 84% of women had dietary intakes of vitamin E below the estimated average requirement (EAR) of 12 mg.8 Serum α-tocopherol levels from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) were below normal (30 μmol/L) among 87% of individuals aged 20 to 30 years.9 College students taking multivitamin supplements had higher total intakes of vitamin E, and those students using supplements had substantially higher dietary vitamin E consumption as well.8 Nevertheless, Picciano et al10 found that only 14.2% of adolescents aged 14 to 18 years took multivitamin/mineral supplements (NHANES 1999-2002).
Possible reasons for this inadequacy of dietary vitamin E intake include avoidance of foods containing fats and oils, such as nuts, seeds, and vegetable oils (including full-fat salad dressings), which have some of the richest sources of vitamin E per serving. In addition, if individuals are not aware of these excellent vitamin E sources, their intake of this important nutrient could be limited. Finally, subclinical vitamin E deficiency has few noteworthy symptoms, and therefore it can go undetected more easily.
It is imperative that individuals be informed about the need for dietary vitamin E and where to find it, along with its major roles in maintaining health throughout the life cycle. A basic nutrition course is one platform for introducing college students to this critical antioxidant nutrient and to provide examples of rich food sources that can be easily incorporated into daily meals and snacks. Often, however, within broad introductory nutrition courses, it is easy for vitamin E to be overshadowed by other topics.
This preliminary study was designed to examine students' baseline understanding of and familiarity with the roles of vitamin E and important food sources, to examine the intake of vitamin E through 3-day dietary records among college students along with a short vitamin E-rich food assessment tool, to provide focused education on this essential nutrient, and to test whether this emphasis on vitamin E was conveyed effectively by administering a final posttest to students at the end of the semester.
Measurement tools used for this project included the following:
- Demographic data sheet: a 1-page set of questions inquiring about age, major, residence (on- vs off-campus), dietary practices, and related areas.
- Pre-/post-test: a 20-question pretest covering questions about vitamin E functions and rich food sources (see the Appendix).
- Initial/final vitamin E-specific food frequency questionnaire (EFFQ): an instructor-designed, newly developed, short assessment tool consisting of 15 items representing healthy, vitamin E-rich food choices (each ∼3 mg of vitamin E) for recording daily, weekly, or monthly intakes (see the Appendix). Any additional vitamin E contribution from specific, fortified breakfast cereals was then included, each checked for vitamin E amounts per cup and added to the total after frequency was taken into account. Total vitamin E intakes (milligram α-tocopherol) were then calculated in an Excel program.
- Three-day diet records: a standard, 3-day food record, covering foods consumed during 2 weekdays and 1 weekend day.
The instructor (J.L.) specifically designed tools (a) through (c) for this study.
The Committee for the Protection of Human Subjects approved this study. During week 2 of the semester, undergraduate students enrolled in the introductory nutrition course were introduced to the study and invited to participate. Following informed consent, students completed the demographic data sheet and subsequently the pretest. After the test was collected, students filled out the EFFQ (initial).
Subsequently (week 4), students completed 3-day dietary records as part of a regular, graded assignment for the course. Records were analyzed using ESHA Food Processor Nutrition Analysis, version 11.2 (Salem, Oregon). Any food items having incomplete vitamin E data in the program were analyzed using the US Department of Agriculture data base11 and/or nutrient composition tables.12
During week 5 of the course, a special Food Tasting Day was held, with vitamin E as the focus. A full-color brochure was given to each student, and a vibrant, PowerPoint slide presentation highlighted all aspects of vitamin E. These educational tools were designed and presented by a graduate assistant (E.Z.), a candidate for an MS degree in community nutrition who holds a BS in nutrition and dietetics. Students then enjoyed food samples of excellent vitamin E sources, including roasted sunflower seeds, almond-based snack bars, dried apricots, guacamole, and tortilla chips. A question-and-answer period with the course instructor and graduate assistant followed.
Throughout the remainder of the course, vitamin E information was presented whenever appropriate, and connections were drawn with other nutrients and health concerns (see Table 1). For example, during the introduction to lipids, students were reminded that fat must be present for effective absorption of vitamin E. Coverage of the antioxidant nutrients included a second, in-depth presentation on vitamin E, along with a focused worksheet. Toward the end of the semester (week 13), the posttest and a final EFFQ were administered. All participant responses were kept anonymous.
The data were analyzed using a standard statistical package (IBM SPSS Statistics for Windows, version 24, Armonk, New York). Descriptive statistics were evaluated. Log transformations were used to normalize the data for nonnormally distributed variables. Pearson correlations were used to assess the degree of association between estimated vitamin E intakes and other nutrients, as well as between the vitamin E (α-tocopherol) intakes computed from the 3-day dietary record versus that of the EFFQ. Paired t tests were used to compare pre- and posttest scores of knowledge and initial versus final EFFQs. χ2 tests were used to examine any differences in estimated vitamin E and demographic and dieting practice variables. P values < .05 were considered statistically significant.
Out of 89 students, 52 (58%) agreed to participate in the study. Six students were excluded, 3 because of missing more than 5 classes, and 3 for having 3-day dietary records that were improperly completed (using ounces for volume portions, having only 2 or 3 items per day, and the like). The final sample size of 46 (52% of the class) included 32 females and 14 males, aged 19 to 23 years (mean 20.5 years). Thirty students lived on campus, and 16 lived off-campus. The average number of semesters that students had been at the university was 3.1, ranging from 1 to 7 semesters. Students were mostly majoring (and/or minoring) in an area of health science (nutrition, sports/fitness). The mean age of participants in years ± standard deviation was 20.5 ± 1.0 years, with 30% males (n = 14) and 70% females (n = 32). Sixty-five percent lived on-campus (n = 30) and the balance lived off-campus (n = 16). The participants primarily held the following majors: 24% (n = 11) in prephysical therapy, 22% (n = 10) in nutrition, 20% (n = 9) in athletic training, and 9% (n = 4) in exercise science.
The mean 3-day average vitamin E intake was 10.8 mg (range: 2.2-50.1 mg); the intake was 3.7 mg higher for males than for females (13.4 vs 9.7 mg), although this difference did not reach statistical significance (see Table 2). Only 13 individuals (28%, 4 males and 9 females) reached or exceeded the EAR of 12 mg [18 IUs] and only 8 individuals (17%, 2 males and 6 females) reached or exceeded the Recommended Dietary Allowance (RDA) of 15 mg [22.4 IUs]. The number of vitamin E-rich foods consumed and the corresponding intake of vitamin E, as estimated by the EFFQ, were higher at the end of the semester. Average vitamin E estimates from the initial EFFQ increased from 7.8 to 9.7 mg (P < .001) by the end of the semester (see Table 2). The final test score of vitamin E knowledge was 81%, much higher than the initial test score of 58% (P = .006), reflecting a 40% increase.
According to the 3-day dietary records, vitamin E intakes increased with calorie intake (r = 0.52, P < .001) and were strongly correlated with total fiber (r = 0.74, P < .001). No association was seen between vitamin E intakes and cholesterol. Other noteworthy correlations were between vitamin E and protein (r = 0.51, P < .001), carbohydrates (r = 0.36, P = .01), and fat (r = 0.54, P < .001). However, as a percent of calories, carbohydrate was negatively correlated with baseline vitamin E intake (r = −0.35, P = .02), while fat remained positively associated (r = 0.37, P = .01).
No statistically significant differences in vitamin E intakes for 3-day dietary records or EFFQ were noted between those students living on- versus off-campus, between those who ate standard American diets compared with ethnic diets, or between those describing themselves as “following a weight-loss diet” versus those who were not.
The estimated vitamin E intake from the EFFQ was modestly correlated with the 3-day average of vitamin E (r = 0.35, P = .02). Seventy-six percent, 35 of the 46, were correctly identified as being either above or below the EAR on both EFFQ and 3-day dietary records. Thirty-seven of the 46 (80%) were correctly identified with regard to intakes above or below the RDA for both assessment tools.
None of the students reported taking a vitamin E supplement. Twelve individuals (3 males and 9 females) reported taking a vitamin E-containing multivitamin more than once a week, but among these, only 7 students reported daily use. Estimated vitamin E intakes were slightly higher in supplement users than in nonusers (11.5 vs 10.6 mg), respectively, but this difference was not statistically significant.
As shown in Table 3, the most commonly eaten vitamin E-rich foods among college students were peanuts and peanut butter; other popular items were spinach, tomato sauce, canola oil, olive oil, and almonds. None of the participants reported consuming dried apricots even once a month. Few (n = 5) reported consuming fortified breakfast cereals at least once a week, and this number did not change at the time of follow-up. On the final EFFQ, the number of students reporting at least weekly consumption of several vitamin E-rich foods increased, and in some cases substantially, by the end of the semester. Peanuts and peanut butter continued to be the most frequently consumed items, followed by canola and olive oils, spinach, and tomato sauce. The number of students eating sunflower seeds increased considerably, from 10 at the beginning of the study to 21 students at the end of the study (110% increase); other large increases in consumption included avocado, asparagus, and sweet potatoes, as shown in Table 3.
Food surveys continue to report inadequate vitamin E intakes for all age groups, from young children6 to adults.6 , 13–16 More than 60% (and up to 90%) of the US population may not be obtaining the EAR for vitamin E.6 The 1994-1996 Continuing Survey of Food Intakes by Individuals showed that vitamin E intakes among those 20 years and older were only 6.7 mg for males and 4.7 mg for females.13 Chun et al17 reported average vitamin E intake among adults (ages 19-30 years) to be 6.8 mg from food and 2.8 mg from supplements (NHANES data from 1999-2000 and 2001-2002). Mean intakes of vitamin E among 12- to 19-year-olds were 9.3 mg for males and 6.7 mg for females; among those aged 20 to 29 years, intakes were 11.6 mg among males and 8.0 mg among females (NHANES 2013-2014).7 In the present study, average intakes for 19- to 23-year-old males and females were 13.4 and 9.7 mg, respectively.
College students face many challenges when it comes to achieving nutrient adequacy and following the dietary guidelines.8 , 18 The college setting also provides an opportunity to address this shortfall through focused nutrition education. In this small, preliminary investigation, a nutrition course emphasizing vitamin E led to enhanced knowledge and translated into modest behavioral changes. In the present study, college students were found to have little initial awareness about the role of vitamin E along with rich food sources. Through food sampling and other vitamin E-focused activities throughout the semester, students were able to appreciate the importance of this nutrient and the wide variety of options for achieving vitamin E adequacy. Smith et al19 confirmed the effectiveness of guided imagery activities in enhancing both posttest scores and student confidence in their mastery of material in an introductory nutrition course. In the present study, increased information was also related to an increase in the variety of vitamin E-rich food choices.
Since many of the rich food sources are higher in fat,13 students need to be educated as to appropriate macronutrient percentages, cautioning against a diet too low in fat, often a concern in students trying to maintain a healthy weight. Indeed, as expected, in the present study, percentage of calories from carbohydrate was negatively associated with vitamin E, while % calories from fat and total calories were positively associated with vitamin E intake. As young adults attempt to control their intake of fat and caloric intakes, vitamin E may be sacrificed. Another helpful teaching element was educating students that there are other, lower-calorie, rich vitamin E food choices, such as green vegetables, including spinach, as well as tomato sauce, dried apricots, fortified breakfast cereals, and sweet potatoes.
Strengths and limitations of the study
The EFFQ provided a quick assessment to begin a dialogue and served as an educational tool for healthy, vitamin E-rich options. Foods such as pies, potato/tortilla chips, and other foods fried in oil were not assessed, to keep the EFFQ simple and to emphasize more healthful sources of the nutrient. Therefore, the EFFQ is likely to have underestimated the potential vitamin E intakes of college students, while serving as a teaching tool. Furthermore, highly processed foods, particularly those involving repeated frying, are likely to have reduced levels of vitamin E, which can be destroyed in the frying process.20 The sample size of the study was small, and the participants reflected slightly over half the total number of class members, and, among them, the variation in dietary intakes was substantial. Therefore, the results may not be widely generalizable. Finally, α-tocopherol from food was the focus of this preliminary investigation, and future studies need to review the intakes of supplemental vitamin E as well as the other tocopherols and tocotrienols, as their importance is becoming increasingly recognized.21 Despite these limitations, however, this study revealed the need to place emphasis on this critical, fat-soluble nutrient in introductory nutrition classes for college students. It also reinforces the importance of experiential food sampling to assist in food-related behavior change plus providing a solid awareness and educational experience.
The importance of lifelong vitamin E adequacy cannot be overstated. Introductory nutrition courses provide an important opportunity to educate young adults about the key food sources and interesting physiological role of this nutrient. Promoting the lifelong consumption of vitamin E-containing foods encourages the incorporation of fiber-rich plants and plant oils and enhances awareness of the diet's role in brain health. A short list of healthy, high-vitamin-E foods, along with taste testing, can serve as a springboard for semester-long discussions and nutritional improvement.
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