Key factors for inappropriate supplement intake in risk-taking users: An exploratory sequential mixed-methods pilot study in Japan

This study identified the control factors of inappropriate supplement intake to support public agencies in preventing health problems. We used an exploratory sequential mixed-method design with the integrated behavioral model (IBM). Control factors in the IBM were identified with 95 participants. The highest impact behavioral change was established for the following two out of 19 control factors: "I trust others' blogs as a source of information when they post the bad as well as the good" (<i>r</i> = -0.324, <i>p</i> < 0.001) and "I can control any health problems by adjusting the amount and frequency of my supplement intake" (<i>r</i> = -0.308, <i>p</i> < 0.001). The findings suggest that when providing safety information on supplement use, it is important to: (1) disseminate information to online communities of supplement users who share knowledge based on real experiences and (2) effectively demonstrate the risks associated with continued supplementation.