An experimental study of source and engagement cues for susceptibility to dietary supplement misinformation

Misinformation is increasingly recognized as a public health threat. Still, dietary supplements remain an underexplored domain despite widespread misinformation on social media and documented harms from misuse. This study examined susceptibility to dietary supplement misinformation and the influence of source type and social engagement cues.

It was hypothesized that misinformation would be perceived as more reliable when attributed to a health professional (vs. influencers) and when accompanied by high (vs. low) engagement. It was also expected that these effects would be mediated by perceived source credibility and social consensus, respectively. To study this, a high-powered experimental study was conducted among 1,298 Dutch-speaking adults measuring perceived reliability across 10 mock social media posts about dietary supplements, including five misleading and five non-misleading claims, classified according to the Dutch Keuringsraad Claims Database.

Posts varied by source (fictional health professional vs. fictional influencer) and engagement (low vs. high likes and comments; both between-participants manipulations). Results showed little differentiation in participants’ perceived reliability between misleading and non-misleading posts. Misleading claims attributed to health professionals were consistently evaluated as more reliable than those from influencers, an effect largely explained by perceived source credibility.

However, social engagement cues did not influence reliability judgments of misleading posts and there was no mediation by social consensus. These findings suggest that individuals may struggle to distinguish misleading from non-misleading claims about dietary supplements on social media. This underscores the importance of credible sources and highlights the responsibility of health professionals when communicating about dietary supplements online.

This work was funded by a Leiden University Kiem Grant [KIEM-24-65]. Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioural Sciences, Leiden University, Leiden, The Netherlands Hidde Roovers, Marieke A. Adriaanse & Laurens C. van Gestel Health Campus The Hague/Department of Public Health and Primary Care, The Hague/Leiden, Leiden University Medical Center, Leiden, The Netherlands Marieke A.

Vos & Laurens C. van Gestel Correspondence to Laurens C. van Gestel. The authors declare no competing interests. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.