Health literacy in dietary supplement use among working-age groups: systematic review and meta-analysis.

Background: Globally, dietary supplement use (DSU) is very popular against COVID19. This study aims to investigate the characteristics of research on health literacy (HL) in DSU and compare HL among working-age groups by reviewing related research between 2011 and 2021 in PubMed, SCOPUS, ClinicalKey, Google Scholar and ThaiJO.

Methods: Twenty-five articles that met the inclusion criteria were selected for study and analyzed using Cohen's d.

Results: The results showed that HL affected dietary supplement (DS) consumption behavior among working-age groups with an average effect size of 0.423 (95% CI = 0.249-0.598), followed by disclosure of DSU with an average effect size of 0.220 (95% CI = 0.087-0.353). No effect was found on awareness of dietary supplement advertisements.

Conclusion: The discovery of such knowledge is a significant contribution to public health, leading to the development of interventions and policies for enhancing HL in DSU e.g. organizing knowledge-sharing workshops on DSU and building support networks across all sectors.