Background & aims: Dietary supplements (DS) are popular in many countries but little data are available on their use by sub-populations such as college students. Since students share a variety of characteristics and similar lifestyles, their DS use may differ from the general population. This study assessed DS use, factors associated with DS use, and reasons for use among U.S. college students.
Methods: College students (N = 1248) at 5 U.S. universities were surveyed. Survey questions included descriptive demographics, types and frequency of DS used, reasons for use and money spent on supplements. Supplements were classified using standard criteria. Logistic regression analyses examined relationships between demographic and lifestyle factors and DS use.
Results: Sixty-six percent of college students surveyed used DS at least once a week, while 12% consumed 5 or more supplements a week. Forty-two percent used multivitamins/multiminerals, 18% vitamin C, 17% protein/amino acids and 13% calcium at least once a week. Factors associated with supplement use included dietary patterns, exercise, and tobacco use. Students used supplements to promote general health (73%), provide more energy (29%), increase muscle strength (20%), and enhance performance (19%).
Conclusions: College students appear more likely to use DS than the general population and many use multiple types of supplements weekly. Habits established at a young age persist throughout life. Therefore, longitudinal research should be conducted to determine whether patterns of DS use established early in adulthood are maintained throughout life. Adequate scientific justification for widespread use of DS in healthy, young populations is lacking.
Alex’s Notes: I’m always curious about what supplements people are taking. The supplement industry is huge, and it is always interesting (at least to me) to learn about the various supplements that people take, and even more so to learn about their beliefs that led them to their decision. In 2010, Americans spent $28.1 billion on dietary supplements (DS), with the most popular from 2003-2006 being multivitamins, botanicals, amino acids, and individual vitamins and minerals including vitamins C, E, B6, B12, A, magnesium, and zinc. So clearly the supplement industry is doing well.
But why do people take these supplements? Previous surveys indicate that people use DS to promote general health, enhance performance and energy, and to improve nutrition. Moreover, they reasoned that supplements were good for them and that they wanted to change their lifestyle. It appears that DS user intentions are well placed, but unfortunately the information presented over the internet, TV, radio, and general media is confusing and often contradictory. Moreover, the FDA has no say in the supplement industry and its regulation. But I digress. The current study was conducted to assess the extent of DS usage in five U.S. universities as well as the reasons for students’ usage.
Five U.S. universities were sampled in 2009 and 2010 for this study: University of Massachusetts Amherst (UMASS), MA; Kent State University (Kent State), OH; California State University Fullerton (Cal State), CA; Louisiana State University (LSU), LA; and Tufts University (Tufts), MA. The final sample included surveys from 1248 students.
“A total of 47 questions were included on the paper and pencil survey instrument, 14 of these directly addressed the use of DS. The survey included detailed questions on types of DS, frequency of use, reason for use, and money spent on DS. Ninety-two supplements were listed on the survey, which included 56 general supplement types such as multivitamins, combination antioxidants, and specific vitamins and minerals, as well as 36 specifically-named supplements. Participants were instructed to write in supplements they used but were not listed. Before data analysis, individual supplements and supplement types were grouped into standardized categories. Those DS that could not be placed in another category were termed “other”. The survey instrument also assessed use of sports drinks, sports bars or gels, and meal-replacement beverages, products that are not considered to be DS for regulatory purposes. The instrument included questions regarding reasons for use of each DS product, specifically: performance enhancement, general health, promoting energy, weight loss, increasing endurance, improving muscle strength, unsure, and other.”
General Supplement Usage
Okay, so 66% of the students reported using any type of DS, with 34.8% using any type of sports drink. General DS usage was significantly greater in students on a high-protein diet, a low-fat diet, who exercised >300 minutes per week, exercised in order to increase muscle mass or to relieve stress (but not for strength performance surprisingly), and in those who had better overall fitness level.
Going to the extreme, 11.8% of students took 5+ supplements at least once a week, and this was far more common in the same groups of students listed above for general supplement usage. Additionally, 5+ supplements was twice as common in males as females, about 2.5 times as prevalent in those looking to build muscle compared to losing or maintaining weight, and more common in current smokers than former or never smokers.
All in all, this supplement usage led to an average monthly expense of $17. Although, the standard deviation was $34, which strongly suggests this low average was brought down by the 34% of non-supplement users that reported spending zero dollars per month. Statistically, that would mean that 65% of the students spent between $0 and $51 per month, while 95% spent $0 to $84 per month. We can see how age played a role in this, as the average monthly expense was $29 in students over 23 years old, $15 in those 20-22 years, and $13 in those 16-19 years. Twice as many males spent over $30 per month than females. Interestingly, the greatest monthly expense was seen in those classified as overweight and obese based on BMI, yet it was also over twice as great in persons looking to gain weight rather than lose or maintain. It was also three times as high in those on a high-protein diet.
Breaking it down, the most common dietary supplement was a multivitamin (41.8%), followed by individual vitamins or minerals (28.6%), “other” (23.7%), proteins and amino acids (17.1%), herbals (8.7%), combination products (6.1%), and purported steroid analogs (0.9% - literally just 11 students). For the “other” category, the most common DS was caffeine (16%), followed by fish oil (8%), Echinacea (5%), creatine (5%), and melatonin (1%). Wow, we need to educate more students on the benefits of creatine and melatonin.
For the multivitamin, usage was 73% more likely in students following a high-protein diet, and 42% more likely in those who exercise for stress relief. Amusingly (for whatever reason), protein & amino acid DS usage was 187% more likely in males than females, nearly 3-fold more likely in students following a high-protein diet, and 157% more likely in those who exercise to increase muscle mass. Similarly, the likelihood of spending over $30 per month on DS was 2-fold greater in students looking to gain weight, following a high-protein diet, and exercising to gain muscle mass.
This is my favorite part. While the responses from a survey will of course be limited, hearing the rationale for DS usage is not only insightful, but can often be quite amusing. The same can be said for why people avoid certain supplements, although that wasn’t surveyed in this study.
Anyways, 73% of the students took any DS in order to promote general health, while 29% did so to provide more energy, and 20% did so to increase muscle strength. About 5% indicated they weren’t sure why they took any DS. General health promotion was by far the largest rationale in favor of multivitamin usage (87.5%), although 10% indicated they took one for performance enhancement (?????????). The protein usage was of course greatest in those looking for greater muscle strength (70%), performance (31%), and general health (25%). The “other” supplements were justified by giving more energy, which seems on track given that caffeine was the most common. However, a solid 30% did so for general health, which makes me wonder why only 5% and 1% were taking creatine and melatonin, respectively.
Finally, the justification of the steroid analogs was somewhat amusing. I especially liked that 18% (2 students) did so to promote general health, give more energy, and help with weight loss. Four students did so for performance enhancement, and the majority eight students did so for greater muscle strength.
Oh, almost forgot. The most common source of information was the internet, followed by friends and family. Females relied more heavily on family, health professionals, and TV than did men, while men relied more heavily on the internet, friends, magazines, and store salespersons.