Gender and Education Influences on Dietary Supplement Awareness in Poland: A Nationally Representative Survey

Introduction

Dietary supplements (DS) are a group of preparations that are extremely popular and are increasingly used by patients in various age groups around the world [1–3]. The wide selection, high availability, and affordable prices are key factors influencing the choice of supplements and their inclusion in the daily diet [4]. In Poland, 78% of adult consumers declare using dietary supplements, with nearly half (48%) using them regularly [5]. Additionally, it is common for Poles to take more than one supplement per day. For example, 31.7% of users report taking two products daily, while 8.3% consume five or more [6]. The most frequently used dietary supplements include vitamin and mineral preparations [7].

Dietary supplements are defined under the Food and Nutrition Safety Act, which is based on the European Union (EU) directive. According to this definition, dietary supplements are food products that are intended to supplement the normal diet and provide concentrated sources of nutrients or other substances with a nutritional or physiological effect, taken in measured doses like capsules, tablets, or liquids [8,9]. This definition encompasses a wide variety of supplements, extending beyond the commonly known vitamin and mineral preparations. It includes products such as melatonin, fish oil, probiotics, and coenzyme Q10 (CoQ10), which are often used to support specific health goals like sleep regulation, heart health, and digestion. Additionally, workout supplements, including protein powders, creatine, and branched-chain amino acids (BCAAs), are widely available and commonly used by individuals aiming to enhance physical performance and recovery.

In Poland, the wide availability of dietary supplements is largely driven by the current regulatory framework. Manufacturers are granted considerable freedom in the production and sale of these products, provided they comply with the Food and Nutrition Safety Act. The legislation ensures that dietary supplements are marketed solely for preventive or supportive purposes and explicitly prohibits supplements from making therapeutic claims [10]. Before a dietary supplement is placed on the Polish market, manufacturers must notify the Chief Sanitary Inspectorate (GIS), which oversees the safety and quality of products. While this regulatory system provides a level of oversight, the control primarily occurs through post-market surveillance, meaning supplements do not undergo the same stringent pre-market approval processes as pharmaceuticals. This can raise concerns about the consistency and reliability of some products, despite the established safety standards.

In contrast, the regulatory environment for dietary supplements in the United States is less stringent. Under the Dietary Supplement Health and Education Act (DSHEA) of 1994, dietary supplements are categorized as foods rather than drugs, meaning that manufacturers are not required to demonstrate the safety or efficacy of their products before they are marketed. This has led to a less regulated marketplace, where the quality and safety of supplements can vary significantly, and issues such as contamination or mislabeling are more common [11–13]. As a result, U.S. consumers may face higher risks of using poor-quality or potentially unsafe supplements, underscoring the need for stricter oversight.

Given the high prevalence of dietary supplement use, it is crucial that consumers can make informed decisions. In modern health promotion, fostering high levels of health literacy is essential. Health literacy refers to the ability to seek, understand, and apply health information to make informed health-related choices [14,15]. In the context of dietary supplements, health literacy means selecting products independently and responsibly, based on accurate information and an understanding of potential risks. This is particularly important considering the growing amount of misinformation about dietary supplements circulating on the Internet and social media [16]. A well-informed society is better equipped to avoid potential harm associated with the improper use of dietary supplements and to maintain overall good health.

Therefore, the aim of the study is to assess knowledge and practices in the use of dietary supplements by Polish patients. Knowledge of the concept of a dietary supplement, sources of knowledge on this subject and basic issues related to the use of dietary supplements were assessed.

Material and Methods

STUDY DESIGN AND STATISTICAL ANALYSIS:

The study was conducted on March 11, 2024 using the computer-assisted web interview (CAWI) method on a representative random sample of the Polish adult population. The study was approved by the Bioethics Committee at Poznań University of Medical Sciences (Resolution No. 284/23 of March 17, 2023) and was conducted by the Ariadna National Research Panel.

The questionnaire consisted of two parts. The metrics preceding the main questions included questions about gender, age, place of residence and education. Importantly, people practicing a medical profession, e.g. a doctor, pharmacist, nurse, dietitian, were excluded from further questions. This type of exclusion allowed for the collection of a representative group of respondents who reflect the knowledge and attitudes of consumers reaching for dietary supplements.

The second part of the questionnaire contained questions about dietary supplements. Respondents were asked whether they knew and understood the concept of a dietary supplement. They made their assessment based on a 5-point Likert scale. Then they were asked about the source of information about supplements, the place where they made their purchases and whether they consulted their choices with a specialist, e.g. a doctor or a pharmacist. Answers indicated based on a cafeteria of answers with the possibility of multiple choice. Other questions on a 5-point Likert scale concerned, among others, the safety of supplements and their origin, interactions with medications and other supplements taken, and knowledge of the differences between dietary supplements and over-the-counter drugs.

The statistical analyses have been performed using the statistical suite StatSoft. Inc. (2017). STATISTICA (data analysis software system) version 13.0. www.statsoft.com.

The quantitative variables were characterized by the arithmetic mean of standard deviation or median (1^st–3^rd quartile) or max/min (range) and 95% confidence interval. The qualitative variables were presented with the use of count and percentage.

To check if a quantitative variable derives from a population of normal distribution the W Shapiro-Wilk test has been used. To determine dependence, strength, and direction between variables, Pearson’s chi-square test and Cramer’s V. In all the calculations the statistical significance level of p=0.05 has been used.

SAMPLE:

The study involved 1074 participants, over half of whom were women (53.26%), with a median age of 46 (32–59) years. The youngest participant was 18 years old, while the oldest was 94. Virtually all respondents had secondary (40.97%) or higher education (45.90%), with none of them having medical education. The largest group of participants were residents of villages (37.52%) (Table 1).

Results

Most respondents agreed (48.70%) or strongly agreed (23.09%) with the statement “I understand and know what a dietary supplement is” (Figure 1). Women (p=0.001) and individuals with higher education (p<0.00001) were more likely to agree with this statement – both of these dependencies are weak.

The main source of knowledge for respondents about dietary supplements was the Internet (38.64%), however, other mass media (except for radio) as well as medical professionals were almost equally popular sources (Figure 2). Men more often than women obtained knowledge about dietary supplements from the radio (p=0.04) and television (p=0.01) – both dependencies are weak. Television was also preferred by individuals with lower education (p=0.0006) – weak dependency. Information from the press was mainly obtained by people over 45 years old (p<0.00001, rather weak dependency) and those with higher education (p=0.001, weak dependency). Doctors were a more popular source of information in larger towns (p=0.03, weak dependency) and among individuals with higher education (p=0.007, weak dependency).

Over half of the respondents purchase dietary supplements most often in brick-and-mortar pharmacies (61.64%). Among frequent sources of these products, online pharmacies (28.03%) and online shopping portals (18.99%) should also be mentioned (Figure 3). Brick-and-mortar pharmacies were more often chosen by women (p<0.00001, weak dependency), while online pharmacies were preferred by men (p=0.0002, weak dependency), individuals from larger towns (p=0.005, weak dependency), and those with higher education (p=0.002, weak dependency). Dietary supplements in supermarkets were more frequently purchased by men (p=0.002, weak dependency). Online shopping portals were more commonly used by individuals aged 25–44 (p<0.00001, weak dependency). Drugstores were significantly more often used by individuals under 34 years old (p<0.00001, weak dependency). Women more often than men (p=0.02, weak dependency) used herbal shops for this purpose, while men more often chose gyms (p=0.008, weak dependency).

Only one in five respondents (20.48%) believes that advertising influences their decision to purchase dietary supplements, but nearly one in three often relies on advice from family and friends in this aspect (36.12%) (Table 2). Women (p=0.03, weak dependency) more often, while individuals with higher education less often (p=0.0008, weak dependency), were guided by advertisements when purchasing dietary supplements. Also, women (p=0.02, weak dependency) more often relied on recommendations from friends/family in this aspect.

Consulting the intake of dietary supplements with specialists was not a common practice among the respondents - nearly one in four never did it (23.46%), while only one in twenty always did it (6.80%) (Figure 4). Women more often did so (p=0.0002, weak dependency), as did individuals with higher education (p=0.02, weak dependency). If the respondent consulted the intake of dietary supplements with a specialist, it was most often a doctor (36.96%) or a pharmacist (32.77%). Women more often used consultations with a doctor in this aspect (p=0.002, weak dependency), as did older individuals (p=0.004, weak dependency) and those living in larger cities (p=0.003, weak dependency). Consultations with a pharmacist were also more popular among women (p=0.02, weak dependency). Individuals over 55 years old less frequently than others did not consult the intake of supplements with any specialist (p=0.006, weak dependency).

Most respondents (56.79% and 68.25%) disagreed with the statements that dietary supplements are medicinal products and can replace a balanced diet (Table 3). Individuals with higher education (p=0.0004, weak dependency) more often than others believed that dietary supplements are medicinal products, while men (p<0.00001, weak dependency) more often believed that they can replace a balanced diet. Slightly less than three-quarters of the respondents (69.19%) believe that dietary supplements can complement a normal diet, while only close to one-third of them (36.13%) consider them as food products. Individuals with higher education (p=0.00001, rather weak dependency) more often believed that dietary supplements can complement a normal diet. The most diverse responses were obtained for the statement “Dietary supplements provide a nutritional effect” – close to one-third of respondents agree, disagree, or have no opinion on this aspect.

Most respondents believe that dietary supplements with the same ingredients may vary in quality (63.69%) and should be purchased from reputable sources (81.28%) (Table 4). Women more often agreed with the first statement (p=0.0007, weak dependency), as did individuals with higher education (p<0.00001, rather weak dependency), while women (p<0.00001, weak dependency) and individuals with higher education (p<0.00001, rather weak dependency) more often agreed with the second statement. Only one-third of respondents (35.11%) believe that dietary supplements from well-known manufacturers have better quality, while nearly half of them could not take a stance on this issue (46.37%). The most diverse responses were obtained for the statement “Dietary supplements are as safe as medicines” – close to one-third of respondents agree, disagree, or have no opinion on this aspect – men (p=0.0001, weak dependency) more often agreed with this statement.

Most respondents believe that dietary supplements may interact with other medicines or supplements (62.66%) and may affect the action of drugs prescribed by a doctor (62.20%) (Table 5). Women more often agreed with the first statement (p=0.001, weak dependency), as did individuals with higher education and secondary education (p<0.00001, rather weak dependency), while women (p=0.005, weak dependency) and individuals with higher education (p<0.00001, rather weak dependency) more often agreed with the second statement. A decisive majority of respondents familiarize themselves with the information on the packaging of the dietary supplement (66.01%), while less than half of them believe that these packages look the same as those of medicines (39.94%). Women (p=0.00003, weak dependency), individuals over 55 years old (p<0.00001, rather weak dependency), and those with higher education (p=0.007, weak dependency) more often read the information on the packaging of dietary supplements. Individuals with higher education and secondary education (p=0.01, weak dependency) more often believe that the packaging of dietary supplements looks the same as that of medicines.

Discussion

The results of the study indicate that most respondents believe that they understand and know what dietary supplements are. Women and people with higher education are more likely to declare understanding of the topic of dietary supplements. This suggests that education and can influence better orientation in health issues, which is consistent with previous studies indicating a higher level of health awareness among educated women [17,18]. On the other hand, considering that the consumption of dietary supplements may be greater among men, these results should be particularly considered [19]. The results of our study on awareness and behavior related to dietary supplements are consistent with the results of other studies conducted in Europe in recent years. Data analysis shows that most respondents declare knowledge about dietary supplements, which is confirmed by other studies [20], although Kołodziej et al indicated that men have greater knowledge in this area [21]. Only 20.48% of respondents in our own study believe that advertising influences their purchasing decisions regarding dietary supplements, while 36.12% often base their choices on the advice of family and friends. People with higher education are less likely to be guided by advertising, which may indicate a more critical approach to promotional content. These results should be compared with the research by Karbownik et al, who found that Polish Internet users without medical education have false beliefs about dietary supplements. These people trust advertising and this may be a source of false information about supplements [22].

Health literacy, defined as the ability to access, understand, evaluate, and apply health-related information, plays a crucial role in enabling consumers to make informed decisions about dietary supplements. Our findings show that respondents with higher education demonstrate greater critical thinking towards advertising and are less likely to be influenced by promotional content. This is an indicator of higher health literacy levels, as these individuals are better equipped to evaluate the reliability of information from various sources. On the other hand, the high prevalence of Internet use (38.64%) as a primary source of information, combined with the documented spread of misinformation on social media, highlights the need for improved health literacy across all demographic groups. Enhanced health literacy can help consumers discern credible sources of information and make safer, more informed choices regarding the use of dietary supplements, especially in light of potential risks associated with incorrect usage.

In light of growing consumer interest in dietary supplements, it is essential to consider parallels in health education and awareness across various health conditions and preventive measures. Studies show that consumers who make informed decisions about health products, such as dietary supplements, demonstrate higher health literacy, enabling them to differentiate between credible and non-credible sources. Similarly, findings from research on antibiotic resistance genes in methicillin-resistant Staphylococcus aureus (MRSA) strains and carbapenem-resistant Klebsiella pneumoniae emphasize the importance of educating both patients and healthcare professionals on the risks associated with inadequate knowledge and misuse of health products, whether they are supplements or pharmaceuticals [23,24]. The lack of proper information channels can lead to the spread of misinformation, as seen in cases where patients may assume dietary supplements are inherently safe due to their accessibility and marketing.

Moreover, studies such as those on bacterial vaginosis prevalence in Ethiopia [25] and multidrug-resistant Shigella in pediatric patients in Iran [26] highlight the significant health risks associated with inadequate understanding and misuse of health interventions. These findings underscore the need for critical health education to empower consumers to make informed choices, as these types of misinformation risks are also present in the dietary supplement market.

Ultimately, awareness of antibiotic resistance and pathogen adaptability, as demonstrated in studies like those on antibiotic-resistant Staphylococcus species [27], suggests a parallel need to cultivate critical thinking and knowledge around all health-related products, including dietary supplements. Enhanced consumer education can mitigate potential health risks from both supplement misuse and misinformation, reinforcing the importance of reliable information sources and professional consultation. The main source of information about dietary supplements for respondents is the Internet (38.64%). Publications indicate the growing role of the Internet, including social media, in searching for information about health [28,29], which causes patients to have access to a lot of false information [30]. People over 45 years of age are more likely to use press releases, while people with lower education use television. This is confirmed by other studies, which also suggest that people with higher education are more aware that information provided in advertisements may not be reliable [31]. Doctors are a more frequent source of information in larger cities and among people with higher education. This indicates the importance of access to professional medical care and differences in information preferences depending on demographics. Consulting specialists about the use of dietary supplements is not a common practice – only 6.80% of respondents always do it, and 23.46% never do it. Women and people with higher education consult doctors more often, which may indicate better health care in these groups. Consultations with pharmacists are also popular, especially among women. The lack of consultations among people over age 55 may indicate confidence in their own knowledge or shopping habits.

Respondents in our own research most often buy dietary supplements in traditional pharmacies (61.64%), which emphasizes trust in these places as sources of safe and authentic products. Other studies confirm that pharmacies are the main place to buy dietary supplements [19]. In our study, online pharmacies (28.03%) and online shopping portals (18.99%) are also popular, especially among men, people with higher education and residents of larger cities. Supermarkets and drugstores are preferred by younger people and men, which may indicate convenience and availability as key factors in the choice. Women use herbal medicine shops more often, which may be due to a greater interest in natural methods of supporting health. Interestingly, a Dutch study showed that access to information on dietary supplements varies greatly, depending on the point of sale [32].

Most respondents disagree with the statement that dietary supplements are drugs (56.79%) and that they can replace a balanced diet (68.25%). This positive attitude suggests that consumers are aware of the limitations of dietary supplements and their role as a complement to, not a substitute for, a healthy diet. Most respondents agree that dietary supplements with the same ingredients may differ in quality (63.69%) and that they should be purchased from trusted sources (81.28%). Women and people with higher education are more likely to share this opinion. Almost half of respondents have no opinion on the quality of supplements from well-known manufacturers (46.37%), which suggests the need for more consumer education in this area. On the issue of dietary supplement safety, opinions are divided, which indicates the need for further research and the provision of educational information for consumers.

Dietary supplements, by definition, are foodstuffs, not medicinal products; therefore, the reasons for purchasing dietary supplements by consumers, indicated as factors falling under the category of “disease prevention”, should not only raise concerns, but above all, constitute an impulse for actions aimed at improving consumer knowledge in this area [33]. Inappropriate use of dietary supplements can be potentially harmful to patients, especially given the uncontrolled information on the Internet and social media [17]. The role that pharmacists play in advising citizens and purchasing these products can help to improve their safer use, but their knowledge, attitudes, and practices on this topic are still largely unknown.

Conclusions

Our research indicates diverse sources of knowledge and preferences regarding the purchase of dietary supplements, which are shaped by various demographic factors. Health education and access to reliable information are key to an informed approach to supplementation. It is also important to increase consultations with professionals to ensure safe and effective use of dietary supplements. Finally, further educational activities are needed to increase consumer awareness of the quality and safety of dietary supplements.