Abstract
Inappropriate use of dietary supplements by patients might exacerbate their diseases. The aim of this study was to clarify the situation of dietary supplement use for disease treatment among patients. A cross-sectional online questionnaire survey was conducted between 18 and 30 November 2022. A preliminary survey revealed that the proportion of patients who used dietary supplements to treat their disease ranged from 7.7% (cancer) to 28.2% (menopausal disorder). In the actual survey, across all diseases, patients who used dietary supplements for treatment purposes were satisfied with their therapeutic effects. Information obtained via the internet was the most common reason given for starting to use supplements. The proportions of patients who used supplements concurrently with medicine ranged from 25.4% (liver disease) to 72.2% (mental disorder). Most users of supplements did not consult with their physicians or pharmacists about them. However, patients preferred face-to-face consultation with a physician or pharmacist when discussing the concomitant use of medicines. In conclusion, the role of pharmacists is important for the appropriate use of dietary supplements among patients, especially concomitant use with medicines. More awareness about dietary supplements is needed for healthcare professionals to consult with their patients.