none3siPurpose – The main objective of this study is to assess the applicability and robustness of the information
motivation behavioural skills (IMB) model in determining dietary supplement usage of pregnant and
breastfeeding women. More specifically, we examine the indirect effects of online social capital and internet use
for health information on dietary supplement usage through self-efficacy and the moderating role of
educational attainment.
Design/methodology/approach – Data was collected from 415 pregnant and breastfeeding Italian women
using a self-administered questionnaire. Hypotheses were tested using Hayes’s (2013) PROCESS macro
for SPSS.
Findings – Internet use for health information is directly associated with dietary supplement usage. Online
social capital and internet use for health information positively influence dietary supplement usage through
self-efficacy. However, the results from moderated mediation analyses show that the mediation effects are
moderated by educational attainment so that indirect relationships were stronger among women with a lower
level of education than among those with a higher level of education.
Practical implications – Dietary supplement marketers and public health agencies can develop and
implement dietary supplement promotional materials and interventions by disseminating information through
the internet and social media and by strengthening social ties on online networking sites.
Originality/value – The originality of this study lies in the use of the IMB model as a theoretical framework to
examine the mediating role of self-efficacy and the moderating role of education in explaining the mechanism of
how online social capital and internet use for health information influence dietary supplement usage.
Keywords Online social capital, Internet use for health information, Self-efficacy, Dietary supplement usage,
PregnancyopenYam Limbu;
Marta Giovannetti;
Silvio CardinaliLimbu, Yam; Giovannetti, Marta; Cardinali, Silvi