Dietary supplement use among seniors: the opinions of pharmacists

Introduction

Nowadays, Hippocrates’ thesis about the possible healing effects of food carries the risk of incorrect interpretation [1]. A medicinal product is a substance intended for treatment of diseases in humans or prevention of these diseases [2], whereas a foodstuff is any substance intended for human consumption [3]. In turn, a dietary supplement is a foodstuff that is a concentrated source vitamins, minerals, or other substances that have a nutritional or other physiological effect [4, 5]. Considering the possibility to produce the above- mentioned products in pharmaceutical, food and chemical plants, and the identity of the ingredients and sometimes their homogeneous form, there is a substantial risk of apparent similarity, simultaneously increasing the risk of interactions between the substances they contain [6]. The Hippocratic perception of food as medicine and medicine as food, in the era of a dynamically developing market of pharmaceutical and food products and dietary supplements, makes it difficult for consumers to correctly identify a product’s intended use. This ambiguity is further compounded by the fact that dietary supplements must meet general quality and safety requirements, which apply to all foodstuffs [7]. Treatment of dietary supplements only as foodstuffs may lead to their abuse and consequently to adverse effects and interactions [8]. Dietary supplements are a group of food products commonly used due to their ease of purchase and belief that they are natural and, therefore, safer than pharmaceuticals [9]. However, issues arise when consumed in excess or combined with other supplements or medications. Furthermore, such interactions are more common in older adults, males, and chronically ill members of the community. Ageing is often accompanied by a gradual decline in physical and mental performance and an increasing risk of disease. Several diseases or other health problems that occur in old age increase the risk of uncontrolled intake of medicines, as well as dietary supplements. Dietary supplements can provide nutrients that may be lacking or insufficient in the diet. However, the high concurrent use of prescription drugs and dietary supplements in older people may increase the risk that drugs will influence the absorption, metabolism, excretion, or storage of nutrients, or, conversely, that nutrients will affect the drugs. Their ramifications span from mild perturbations to severe consequences [10]. Therefore, it is crucial for health professionals to monitor the use of supplements carefully and consider the possibility of harmful interactions or cumulative overdoses to ensure safety of patients. Pharmacists play a key role in ensuring that seniors are correctly taking supplements [11, 12]. Pursuant to the Act of 10 December, 2020 on the profession of a pharmacist, pharmacists carry out professional activities aiming to protect patients’ health and safeguard public health. The tasks of a pharmacist include those related to providing pharmaceutical advice to ensure the correct use of the medicinal product. Additionally, the report entitled ‘Role of pharmacists in the struggle with civilisation diseases’ demonstrates that pharmacy employees support patients in selecting over-the-counter (OTC) medications or supplements, whereas the patients show great interest in pharmaceutical care [13]. The above data highlight the need for more detailed assessment of participation of pharmacists in shaping health behaviours of seniors associated with the intake of dietary supplements, and to ascertain the extent to which the preparations used by seniors meet safety criteria.
The aim of the study was to assess the opinions of pharmacy employees (pharmacists and pharmaceutical technicians) concerning the use of dietary supplements by seniors, and to perform qualitative analysis of dietary supplements available on the Polish market.

Material and methods

In our research the overuse of dietary supplements is defined as the practice of using more than one product from this category [14]. We applied the WHO definition of ‘senior’ to include people aged 60 years and over [15]. The study was conducted in 2023 by the method of a diagnostic survey using an author-constructed questionnaire addressed to pharmacy employees. The survey was voluntary and anonymous. In order to maintain complete anonymity, the research was conducted electronically. Questionnaires were distributed to pharmacists electronically using Google Forms. The study included 140 employees of pharmacies located across Poland. The vast majority of the participants had higher education in pharmacy (pharmacists: 65.7%), followed by pharmaceutical technicians, who constituted 34.3% of respondents. These were primarily young persons (mean age 34 years), with females constituting 81.4% of respondents. Work experience in the profession was mainly up to 10 years. Most participants were employees of pharmacies located in a city near outpatient departments with over 200 patients, nearly half of whom were seniors (47.9%). Table 1 presents detailed data. The study also conducted qualitative analysis of selected dietary supplements. The review focused on products which, in the respondents’ opinions, were most often used by seniors. Based on information provided on the packaging of the products selected for analysis, the correct labelling and intended use of dietary supplements was determined, taking into account the provisions of the Act on Safety of Food and Nutrition [4] and Regulation (EU) No. 1169/2011 of the European Parliament and of the Council of 25 October 2011 on the provision of food information to consumers (…) [7]. Considering the multi-aspect phenomenon related to the intake of dietary supplements by seniors, the study is the continuation of the analysis conducted to date in the field of nutrition and dietary supplementation among seniors, which showed that more than 60% of the seniors reported taking dietary supplements, and nearly half of them considered that supplements are beneficial for health [16].
Statistical analysis with graphic presentation was performed using Excel 2016 and the statistical software STATISTICA (StatSoft Statistica). The results were presented as the mean value (x), and ± standard deviation (SD), or as the percentage of a given population. Calculations were carried out using the non-parametric χ2 test of independence. Considering the use of cafeteria of answers in the form of a Likert scale in the research tool, the direction and strength of the relationship between qualitative variables of a nominal and ordinal type were assessed based on multidimensional contingency tables for investigating the relationships between three or more variables. In addition, in order to obtain more detailed information concerning the detected relationships and simultaneous Type I error control, Bonferroni correction was used. In all analyses, p values ≤ 0.05 were considered statistically significant.

Results

The main aim of the study was to assess the opinions of pharmacy employees (pharmacists and pharmaceutical technicians) concerning the use of dietary supplements by seniors. In the opinions of pharmacists, seniors definitely abuse dietary supplements (42.9%). Based on their knowledge and professional experience, 70.7% of pharmacy employees stated that they are able to verify the risk associated with excessive use of dietary supplements by seniors (combined results for ‘definitely yes’ and ‘probably yes’). Pharmacists declared that purchases of dietary supplements among seniors were common, especially in the group of females, among whom higher interest in such products was observed, compared to males. The mean percentage of senior women who according to pharmacists buy dietary supplements was 72.8%, while among males the percentage of seniors buying dietary supplements was 55.5%. Among seniors, the most popular dietary supplements mentioned by pharmacists were mineral (35.7%) and vitamin supplements (35.7%). The lowest percentage of seniors (24.3%) purchased supplements supporting various medical conditions. Alarmingly, the supplements most desired by seniors were well-known brands (52.1%), and the primary factor influencing seniors’ selection of dietary supplements was product advertising (90%). Table 2 presents detailed data.
Opinions of pharmacists confirmed that they are an important link in the process of health education and shaping health behaviours of seniors concerning the intake of dietary supplements (Figure 1). According to pharmacists, advice on the use of dietary supplements is the responsibility of pharmacy employees (the sum of the declarations ‘I definitely agree and ‘I agree’ was 85.7%). The majority of pharmacy employees were unanimous about the need to have equally high knowledge about dietary supplements as about drugs (total 82.2% of answers ‘I agree and ‘I definitely agree’). Only 17.9% of respondents (including 2.9% of those who definitely did not agree) considered that this knowledge is not equally important in the case of dietary supplements (Figure 1). Statistical analysis showed a statistically significant difference between the number of senior customers in a pharmacy and the belief of the pharmacists employed concerning the necessity for them to possess a high level of knowledge about dietary supplements (c2 = 17.877, p = 0.022). In all groups of pharmacies (irrespective of the percentage of seniors among customers) there was a strong conviction that pharmacy employees should possess knowledge on dietary supplements. The highest percentage of pharmacist employees in pharmacies where seniors constituted more than 60% of customers considered that pharmacy employees should have an equally high knowledge concerning dietary supplements as they have in the case of drugs. In pharmacies where seniors constituted more than 60% of customers, 86.6% of pharmacists replied that they ‘agree’ or ‘definitely agree’ with this assumption. In turn, in pharmacies where seniors constituted less than 50% of customers, the above-mentioned answers were provided by 70.1% of pharmacists (p = 0.021). The above statements indicate that the general awareness and recognition of the role of dietary supplements in pharmaceutical care, especially in the context of their availability and widespread use by patients, play an important role.
Another important aim of the study was to assess pharmacists’ opinions with reference to economic aspects. The majority of respondents declared that dietary supplements are an important source of income for the pharmacy (85.7%) (Figure 1). Statistical analysis demonstrated that the workplace of pharmacists exerts a significant effect on their opinions in this respect (c2 = 26.210, p = 0.001). In urban pharmacies – both far from and near to outpatient departments – the predominant response was ‘I definitely agree’ (48.9% and 54.3%, respectively), whereas in urban pharmacies the dominant response was ‘I mostly do not agree’ (41.7% of pharmacists). Overall, in urban pharmacies (irrespective of the distance to an outpatient department) 89.1% of pharmacists indicated ‘I definitely agree’ or ‘I agree’ that dietary supplements are an important source of income for the pharmacy, whereas in rural pharmacies only 50.0% of pharmacists gave this response (p = 0.0002). However, despite this, the majority of pharmacists (85.7%) indicated that the high price of the pro­duct is not a factor influencing whether they recommend a given product to their customers (as indicated by the responses ‘I definitely do not agree’, ‘I do not agree’, and ‘I mostly do not agree’) (Figure 1).
Concerning the problem associated with abuse of dietary supplements by seniors, the pharmacists were asked about potentially beneficial effects of vitamin supplements on seniors’ health. The vast majority of pharmacists in the study stated that the use of dietary supplements in the situation of their abuse may have a potentially hazardous effect on their health (in total, 77.2% responded ‘I definitely agree’ or ‘I agree’). How­ever, more than half of the pharmacists (53.6%), regarding the question concerning the beneficial effect of vitamin supplements on seniors’ health, responded ‘I definitely agree’ or ‘I agree’) (Figure 1).
A key aim of the analyses was to assess the opinions of pharmacy employees concerning their role while selling dietary supplements to seniors (Figure 2). The results showed that a vast majority of pharmacists (61.4%) reported that they inform seniors concerning the possibility of adverse effects of dietary supplements. Statistical analysis performed using the non-parametric c2 test demonstrated that the duration of work experience of a pharmacist has a significant effect on the provision of information about possible adverse effects and interactions which may occur during the use of dietary supplements (c2 = 12.918, p = 0.011). Among pharmacists who had work experience longer than 10 years, 70.1% responded ‘very frequently’, or ‘always’, or ‘often’ to the following question: ‘In your daily practice, do you inform a senior about adverse effects/interactions which may occur during the use of dietary supplements?’ In contrast, 41.9% of pharmacists who had work experience shorter than 10 years stated the same (statistically significant difference, p = 0.002).
Analysis of pharmacists’ responses concerning obtaining information from seniors about the intake of products from the pharmaceutical market also confirmed a high level of interest of pharmacists. The vast majority of them (68.6%) while selling a dietary supplement to a senior person stated that they asked a question related to these issues (Figure 2). Statistical analysis performed using non-parametric c2 test demonstrated that the frequency of obtaining this information depended on the number of customers of the pharmacy (c2 = 13.446, p = 0.009). A higher percentage of pharmacy employees (50%) serving over 200 customers a day significantly more often stated that while selling a dietary supplement to a senior they asked about other dietary supplements used or drugs ordered by a doctor, compared to pharmacists from smaller pharmacies (less than 200 patients/day), only 23.6% of whom indicated ‘very frequently’ or ‘always’ (p = 0.001).
The study confirmed the expected attitude of pharmacists in the area of monitoring the sale of dietary supplements, the purpose of their use, and potential interactions with other drugs. Only in the case of undertaking interventions in seniors’ purchasing decisions if there are no indications for using the supplement were pharmacists less inclined to take up activities in this respect (more than 47.1% of pharmacists mentioned that sometimes they manage to change the senior’s decision). Figure 2 presents detailed data.
The study also assessed pharmacists’ opinions concerning safe use of dietary supplements by seniors (Table 3). The results present preferences of pharmacy employees regarding dietary supplements which they would recommend to seniors. The highest percentage of pharmacists recommended to seniors vitamin (46.4%) and mineral supplements (42.1%). It should be emphasized that pharmacists also paid attention to the fact that the choice of supplements depends on the individual situation of a patient (20.7%), which may suggest the need for more precise assessment of the state of health and adjustment of supplementation to specific needs (Table 3). More than half of the pharmacists considered that responsibility for the safe use of dietary supplements rests equally with the seniors, their caregivers, and health professionals, including pharmacists.
Opinions of pharmacy employees regarding regulation of activities related to the safe use of dietary supplements indicate several key actions which could contribute to the limitation of abuse of these products by seniors. According to 84.3% of pharmacists, the main action limiting the phenomenon of abuse of dietary supplements by seniors would be a ban on advertising these products in the mass media. Also, pharmacy employees paid attention to the need for education of seniors (62.1%) and the need to reduce these products in non-pharmacy trade (53.6%) (Table 3). Statistical analy­sis demonstrated that the largest number of supporters of the advertising ban were pharmacists in the youngest age group (93.6%), whereas the smallest number was among those aged over 40 (66.7%). A statistically signi­ficant relationship was observed between pharmacists’ chronological age and their opinions concerning a ban on advertising (c2 = 10.218, p = 0.006). A significantly higher percentage of pharmacists aged 25-39 (89.1%) (p = 0.003) considered that a ban on advertising in the mass media would limit unjustified use of dietary supplements by seniors, compared to the group of pharmacists aged over 40 (66.6%).
Qualitative analysis of dietary supplements performed in this study was limited mainly to the verification of compliance with basic legal regulations. Pharmacy staff were asked to list supplements which, in their opinions, were most frequently purchased by persons aged over 60. Ten pharmaceutical products most often mentioned were selected for detailed qualitative analysis. The study showed that five from among ten products analysed possessed the status of proper qualification in the GIS Registry, while in the case of four products no proceedings were conducted (one of them was not included in the Registry), despite the fact that the products have functioned in the Registry for 1-5 years. All products regarding their labelling were in line with the guidelines contained in Regulation No. 1169/2011. The packaging of each product contained a warning regarding not exceeding the recommended daily dose and a statement that dietary supplements cannot be used as a substitute for a diverse diet. The number of active ingredients contained in individual preparations ranged from three to nineteen. More than half of the analysed products (six out of ten) contained in their composition a higher content of active ingredients than the reference intake values set out in EU Regulation No. 1169/2011.

Discussion

The ageing process is accompanied by double-track cellular changes of a primary and secondary nature. Cellular changes in the structure and function which affect organs and systems are defined as ‘primary ageing’, while the changes caused by the interaction of primary ageing with the environment, diet, life style and diseases are defined as ‘secondary ageing’ [17]. The currently observed increase in life expectancy is not positively related to its quality and social functioning [18]. Non-communicable chronic diseases are the leading cause of disability- adjusted life years (DALYs), and the estimated frequency of the occurrence of multimorbidity in persons aged over 60 is 65-98% [19, 20]. Metabolic and physiological changes occurring in the aging body may, one the one hand, exert a negative effect on the state of nutrition and the body’s internal efficiency and, on the other hand, are also the effect of improper life style (including the mode of nutrition). Adjustment of the mode of nutrition promoting healthy ageing may be an important strategy for maintaining physical and cognitive functions, and preventing diseases associated with advancing age [21]. Current recommendations by the WHO indicate that oral dietary supplements in combination with dietary advice may improve the state of nutrition in seniors. This was also confirmed by a study by Chew et al. [22], who indicated that in the case of older people exposed to malnutrition, daily consumption of a specialist dietary supplement containing beta-hydroxy-beta-methylbutyrate (HMB) and vitamin D for six months, together with dietary counselling, considerably improved nutritional and functional results, compared to a placebo supplement applied in combination with dietary counselling. On the other hand, a study carried out among healthy seniors who took daily for 12 weeks a multi-ingredient dietary supplement composed of vitamin B3, C, D, fish oils, resveratrol, olive fruit phenols and astaxanthin showed a limited effect on inflammatory condition and epige­netic markers of biological age in healthy seniors [23]. Other research showed that the chemical molecules contained in dietary supplements have a pharmacological effect which, in consequence, may lead to adverse effects [24]. Dietary supplements may be a beneficial way to supplement nutritional deficiencies, but simultaneously create the risk of adverse effects in the situation of their excessive use and using various sources. The WHO recommendations also emphasize that the use of oral dietary supplements must be adjusted to the needs of an individual person and assessed by a trained employee of the health care system [25].
The present study results demonstrated that verifying seniors’ requirements for particular vitamin-mineral supplements was considered an important aspect of pharmacists’ recommendations (20.7%). On the other hand, pharmacists confirmed an alarming trend among seniors connected with abuse of dietary supplements (42.9%). The responses reported above are in accordance with guidelines indicating that dietary supplementation with calcium or vitamin D deficiency may be appropriate for seniors with deficiencies. As emphasized in the recommendations for the Polish population, in justified cases dietary supplements can only be a periodic supplement to the diet [26].
The primary goal of this study was to assess the opi­nions of pharmacists and pharmacy technicians concerning the use of dietary supplements among persons aged over 60. The study demonstrated an alarming trend for abuse of dietary supplements by seniors. According to the results of the PolSenior2 study, the frequency of supplementation among seniors was 32.1% [27]. A study by Babiarczyk et al. [11] showed that in Poland the problem of abuse of dietary supplements, together with the growing proportion of the population aged over 60, has led to an increase in the consumption of OTC preparations, possibly reflecting the phenomenon of ‘healthism’ in society [11, 28].
An important issue related to the safety of supplementation is the fact that dietary supplements are classified as foodstuffs, but show pharmacological effects; i.e. they are products on the border between medicines and food, which increases the risk of their adverse effect on the body in the situation of taking several preparations [29, 30]. Whether a product is classified as a dietary supplement, conventional food, or drug is based on its intended use, and most often, classification as a dietary supplement is determined by the information provided by the manufacturer [31]. In Poland, an entrepreneur wishing to launch a dietary supplement is obliged to notify the Chief Sanitary Inspector (CSI) of this intention using an electronic means of communication. If the analysis of the submitted notification conducted by the Chief Sanitary Inspector does not give rise to doubts, an entrepreneur receives information that a product has been registered effectively [4, 32]. Dietary supplements are considered safe until proven unsafe. On the other hand, medications undergo a rigorous approval process before entering the market; drugs are considered unsafe until evidence shows they are safe. All medicinal products currently available on the pharmaceutical market may be commonly used only after obtaining a marketing authorization issued by relevant institutions. In Poland, the Office for Registration of Medicinal Products, Medical Devices and Biocidal Products (ORMP) is the national registration authority [33].
The pharmacists in the study unequivocally confirmed that the use of dietary supplements in the situation of their abuse may exert a potentially hazardous effect on health (77.2%). On the other hand, the majority of pharmacists participating in this study (53.6%) agreed with the view presented in Polish dietary recommendations [26] indicating that dietary supplements may constitute a beneficial supplementation to the diet, especially in the population of seniors, where the risk of nutritional deficiencies is higher than in the average adult population. In pharmacists’ opinions, the way to reduce the risk associated with abuse of dietary supplements would be primarily a ban on advertising of such products in the mass media (84.3%), limiting the sale of dietary supplements outside pharmacies (53.6%), as well as increasing health awareness of seniors through education related to proper intake of dietary supplements (62.1%). According to Directive 2001/83/EC of the European Parliament and of the Council, advertising addressed to the general public even regarding only OTC medicinal products may have an unfavourable effect on public health when it is abused or improperly prepared [34]. In addition, television broadcasters and dietary supplement manufacturers developed regulations related to advertising supplements. In the adopted document they were obliged to follow the principle indicating that the advertisement must not falsely suggest a relationship between a dietary supplement and improvement of the state of health, or using the image of any medical specialist [35]. Also, the proposed changes to the Act of 25 August 2006 on nutrition and food safety assume the need to specify the rules regarding presentation or advertising of dietary supplements [36].
According to pharmacists participating in this study, the use of dietary supplements by seniors impacts the economic situation of the pharmacy. In the opinions of 85.7% of respondents, dietary supplements constitute an important source of income for the pharmacy. The findings of IPSOS European Public Affairs show that due to experiences associated with the COVID-19 pandemic, as consumers have become more concerned about their health, sales of products have also increased in the pharmaceutical and dietary supplement sectors [37]. According to the PMR report, in 2022, the value of the dietary supplement market in Poland was almost billion PLN, with a nominal growth rate of approximately 14% [38, 39].
Dietary supplements by definition are not intended to ‘treat, diagnose, or prevent diseases’, but are intended to ‘supplement the diet and differ from conventional foods’ [40]. Therefore, medical staff plays a crucial role in identification of the intake of dietary supplements. The attitudes of pharmacists presented in this study indicate that they constitute an important link in the process of health education. Pharmacy employees who reported that half of their customers are seniors significantly more often stated that this type of activity is their professional responsibility. A vast majority of respondents also stated that while selling a dietary supplement to a senior, they ask about the purpose of the purchased product (68.3%) and other products from the pharmaceutical market used (73.5%). In addition, the pharmacists were aware of their responsibility that they should possess equally high knowledge concerning dietary supplements as in the case of drugs (82.2%). This approach is in accordance with the Global Patient Safety Action Plan 2021-2030 aimed at minimizing avoidable harm for patients and provision of patient safety [41].
Qualitative analysis of dietary supplements performed concerned products which, in pharmacists’ opinions, were most often used by seniors. Qualitative analysis of the selected dietary supplements showed that not all products were included in the GIS Registry for first market notification, and in the case of four of them, to date, no proceedings have been carried out before their introduction to the market. All products complied with labelling guidelines. Alarmingly, nearly all of these products contained active ingredients exceeding the maximum allowable amount. The above analysis was reflected in the results of surveillance carried out by the Supreme Audit Office, which showed that in the case of nearly half of notifications concerning introduction of new dietary supplements to the Polish market (during 2014-2016 this was approximately 6,000 products) the verification process had not been started at all. This meant that with respect to such a large number of dietary supplements introduced to the market, no attempt was made to determine whether these products are safe for consumers [42].
Analyses of databases collected in the course of the study enabled identification of opinions and attitudes of pharmacists concerning the use of dietary supplements by seniors. The study confirmed the key role of pharmacists as advisors in the areas of both education and verification of the demand of seniors for specific preparations. This knowledge can support better prognostication, planning and implementation of health education programmes aimed at limitation of abuse of dietary supplements among seniors. In addition, the phenomenon of abuse of dietary supplements among seniors is reflected by a growing market for these products. The results of qualitative analysis of dietary supplements available on the Polish market confirm the validity of the proposed legislative changes regar- ding the clarification of the sale and advertising of these products on the Polish market. Effective monitoring of the constantly evolving patterns of dietary supplement use, as well as their potential interactions with other substances, requires evidence-based surveillance to ensure the safety of products from both the pharmaceutical and food sectors.
Despite its benefits, the study has limitations due to its opinion-forming nature. Its goal was not to measure actual dietary supplement use among older people, but to gather pharmacists’ views based on their daily work. Although the method used to verify age is standard, it might introduce some subjectivity. However, it is worth noting that the survey included an introduction for respondents (pharmacy employees) that explained the purpose of the study and the criteria related to supplement abuse. It also provided definitions of “elderly person” and “dietary supplement.” The study’s authors assumed that pharmacy employees assessed the age of customers based on their work experience and estimates, taking into account aspects such as communication style, behaviour, and overall impression rela- ted to age.
Furthermore, the analysis used to assess the quality of the most common dietary supplements for older people may be subjective. Market mechanisms, such as loyalty programs, may influence the range of products offered by pharmacies and, thus, pharmacists’ opinions. In view of the above, however, the study included pharmacists from various types of pharmacies (chain, private, urban, and rural), which increased the diversity of responses and reduced the risk of bias in the results.
Despite its limitations, the collected data provide valuable information about the role of pharmacists in observing the health behaviours of older people, particularly given the lack of systemic tools for monitoring pharmacotherapy in seniors in Poland.

Conclusions

In the opinions of pharmacists, seniors definitely abuse dietary supplements. According to their responses, purchases of dietary supplements by seniors were common, especially among females, among whom a higher level of interest in these products was observed, compared to males. Mineral and vitamin supplements were the most popular products chosen by seniors.
Pharmacists were aware of their role in the health education of seniors, and the majority of them considered that they should possess an equally high knowledge concerning dietary supplements as about drugs. Most pharmacists agreed that advising on dietary supplements is part of their professional duties.
According to the opinions of pharmacists, the best way to limit the abuse of dietary supplements would be a ban on advertising in the media. They also indicated the need for education of seniors and reducing the availability of dietary supplements outside pharmacies.
It is necessary to implement educational strategies and programmes to improve the awareness of risks and benefits associated with the use of dietary supplements in order to avoid the abuse of dietary supplements by seniors.

Disclosures

The authors report no conflict of interest.

References