The consumption of dietary supplements among the elderly is on the rise. Despite the potential benefits, a comprehensive understanding of the decision-making processes leading to the consumption is lacking. This study explores the conditions influencing the decision-making and behavioral patterns of older adults related to dietary supplement consumption. Using a qualitative approach, in-depth interviews were conducted with 21 elderly participants from a seniors’ club in Bangkok, Thailand, who had consistently consumed dietary supplements for at least one year. The behavior was classified into five primary categories: enduring use of identical dietary supplements, insufficient regard for health compatibility, replacing medications with supplements, not verifying before consumption, and opting for supplements over medical treatments. These patterns are aligned with the core constructs of the Theory of Planned Behavior (attitude, subjective norm, and perceived behavioral control). Many individuals perceive supplements as pivotal health investments, while others view them as a direct route to robust health. Trusted advice from friends and television significantly influence their choices, with a prevailing sentiment that dietary supplements are generally safe. The high price tag on supplements is often associated with superior quality. The findings highlight the multifaceted nature of dietary supplement consumption decisions among the Thai elderly, suggesting the need for interventions to promote safer and more informed choices.

1. Ajzen, I. (1991). The theory of planned behavior. Organizational Behavior and Human Decision Processes. 50(2). 179–211. https://doi.org/10.1016/0749-5978(91)90020-T
2. Ajzen, I., & Fishbein, M. (2005). The influence of attitudes on behavior. In: Albarracín, D., Johnson, B. T., & Zanna, M. P. (editors). The handbook of attitudes. Lawrence Erlbaum Associates Publishers.
3. Alhazmi, A., Kuriakose, B. B., Mushfiq, S., et al. (2023). Prevalence, attitudes, and practices of dietary supplements among middle-aged and older adults in Asir region, Saudi Arabia: A cross-sectional study. PloS One, 18(10). https://doi.org/10.1371/journal.pone.0292900
4. Alowais, M. A., & Selim, M. E. (2019). Knowledge, attitude, and practices regarding dietary supplements in Saudi Arabia. Journal of Family Medicine and Primary Care, 8(2), 365–372. https://doi.org/10.4103/jfmpc.jfmpc_430_18.
5. Bazhan, M., Shafiei Sabet, F., & Borumandnia, N. (2024). Factors affecting purchase intention of organic food products: Evidence from a developing nation context. Food Science & Nutrition, 12(5), 3469–3482. https://doi.org/10.1002/fsn3.4015
6. Boardman, L., Lockwood, J. L., Angilletta, M. J. (2022). The Future of Invasion Science Needs Physiology. BioScience, 72(12), 1204–1219. https://doi.org/10.1093/biosci/biac080
7. Carpenter, S. M., & Yoon, C. (2011). Aging and consumer decision making. Annals of the New York Academy of Sciences, 1235(1), E1–E12. https://doi.org/10.1111/j.1749-6632.2011.06390.x
8. Chiba, T., & Tanemura, N. (2022). Differences in the Perception of Dietary Supplements between Dietary Supplement/Medicine Users and Non-Users. Nutrients, 14(19), 4114. https://doi.org/10.3390/nu14194114
9. Çoker, E. N., Jebb, S. A., Stewart, C., et al. (2022). Perceptions of social norms around healthy and environmentally-friendly food choices: Linking the role of referent groups to behavior. Frontiers in Psychology, 13. https://doi.org/10.3389/fpsyg.2022.974830
10. Cristea, M., & Gheorghiu, A. (2016). Attitude, perceived behavioral control, and intention to adopt risky behaviors. Transportation Research Part F: Traffic Psychology and Behaviour, 43, 157–165. https://doi.org/10.1016/j.trf.2016.10.004
11. Dwyer, J., Coates, P., & Smith, M. (2018). Dietary Supplements: Regulatory Challenges and Research Resources. Nutrients, 10(1), 41. https://doi.org/10.3390/nu10010041
12. Ekor, M. (2014). The growing use of herbal medicines: issues relating to adverse reactions and challenges in monitoring safety. Frontiers in Pharmacology, 4. https://doi.org/10.3389/fphar.2013.00177
13. Gahche, J. J., Bailey, R. L., Potischman, N., et al. (2017). Dietary Supplement Use Was Very High among Older Adults in the United States in 2011–2014. The Journal of Nutrition, 147(10), 1968–1976. https://doi.org/10.3945/jn.117.255984
14. Han, M., Tan, X. Y., Lee, R., et al. (2021). Impact of Social Media on Health-Related Outcomes Among Older Adults in Singapore: Qualitative Study. JMIR Aging, 4(1), 1–12. https://doi.org/10.2196/23826
15. Huang, W. Y., & Wu, C. E. (2021). Predict the exercise behavior intention of the older adults in Taipei City to promote exercise behavior. Science Progress, 104(S3), 1–13. https://doi.org/10.1177/00368504211042468
16. Kamphuis, C. B., de Bekker-Grob, E. W., & van Lenthe, F. J. (2015). Factors affecting food choices of older adults from high and low socioeconomic groups: a discrete choice experiment. The American Journal of Clinical Nutrition, 101(4), 768–774. https://doi.org/10.3945/ajcn.114.096776
17. Karpinski, C. A., & Milliner, K. (2016). Assessing Intentions to Eat a Healthful Diet Among National Collegiate Athletic Association Division II Collegiate Athletes. Journal of Athletic Training, 51(1), 89–96. https://doi.org/10.4085/1062-6050-51.2.06
18. Kassis, A., Fichot, M. C., Horcajada, M. N., et al. (2023). Nutritional and lifestyle management of the aging journey: A narrative review. Frontiers in Nutrition, 9, 01–19. https://doi.org/10.3389/fnut.2022.1087505
19. Kaur, D., Rasane, P., Singh, J., et al. (2019). Nutritional Interventions for Elderly and Considerations for the Development of Geriatric Foods. Current Aging Science, 12(1), 15–27. https://doi.org/10.2174/1874609812666190521110548
20. Kramberger, K., & Barlič-Maganja, D. (2021). Elderly and dietary supplements: Benefits and Risks. Zdravje Starostnikov/Health of the Elderly, 123–130. https://doi.org/10.26493/978-961-293-129-2.123-130
21. Miles, M. B., & Huberman, A. M. (1994). Qualitative data analysis: An expanded sourcebook, 2nd ed. Sage Publications.
22. Ponphimai, S., & Panomai, N. (2018). Prevalence of dietary supplement consumption for health of elderly in the elderly club, Maharat Nakhon Ratchasima Hospital, Nakhon Ratchasima Province. Journal of Health Research, 21(2), 174–185.
23. Stamatiou, R., Katsafadou, V. S., & Mouratidou, T. (2022). The impact of social media on dietary choices, emotions around food consumption and body image in Greek adolescents and young adults. Public Health and Toxicology, 2(S1), 69. https://doi.org/10.18332/pht/149841
24. Supapon, S. (2020). Behavior and demands of elderly dietary supplement use in Thailand. Journal of Humanities and Social Sciences Nakhon Phanom University, 10(3), 12–21.
25. Tan, E. C. K., Eshetie, T. C., Gray, S. L., et al. (2022). Dietary Supplement Use in Middle-aged and Older Adults. The Journal of Nutrition, Health and Aging, 26(2), 133–138. https://doi.org/10.1007/s12603-022-1732-9
26. Tangkiatkumjai, M., Boardman, H., & Walker, D. M. (2014). Herbal and dietary supplement use in Bangkok: a survey. Journal of Complementary and Integrative Medicine, 11(3), 203–211. https://doi.org/10.1515/jcim-2013-0016
27. Torres, T. de L., Camargo, B. V., Boulsfield, A. B., et al. (2015). Social representations and normative beliefs about ageing (Portuguese). Ciência & Saúde Coletiva, 20(12), 3621–3630. https://doi.org/10.1590/1413-812320152012.01042015
28. Usman, A., & Okafor, S. (2019). Exploring the Relationship Between Social Media and Social Influence. In: Advances in Marketing. Customer Relationship Management, and E-Services. IGI Global. pp. 83–103. https://doi.org/10.4018/978-1-5225-7344-9.ch004
29. Walrand, S. (2018). Dietary supplement intake among the elderly. Current Opinion in Clinical Nutrition & Metabolic Care, 21(6), 465–470. https://doi.org/10.1097/mco.0000000000000512
30. Wickramasinghe, K., Mathers, J. C., Wopereis, S., et al. (2020). From lifespan to healthspan: the role of nutrition in healthy ageing. Journal of Nutritional Science, 9, 1–10. https://doi.org/10.1017/jns.2020.26