Higher Serum Monolaurin Is Associated with a Lower Risk of COVID-19: Results from a Prospective Observational Cohort Study

The COVID-19 pandemic has stimulated the search for effective preventive and therapeutic agents. In recent years, many studies have considered the effects of different nutrients. This study aimed to investigate the association between serum monolaurin levels and the risk of developing COVID-19 among healthcare workers. In this prospective observational cohort study, 2712 healthcare workers from the University Hospital “Maggiore della Carità” in Novara, Italy were enrolled. Participants underwent blood sampling and were followed up for six months to evaluate the protective role of serum monolaurin against COVID-19 infection. Monolaurin levels were quantified using targeted metabolomic analysis. The study cohort consisted of 1000 individuals with a mean age of 46.4 years, predominantly female. Higher serum monolaurin concentrations were significantly associated with a lower risk of SARS-CoV-2 infection at both 3- and 6-month follow-ups. The optimal cut-off value for serum monolaurin, which provides protective efficacy, was identified as 0.45 µg/mL. Higher serum monolaurin levels appear to be associated with a reduced risk of COVID-19, suggesting its potential as a protective dietary supplement against SARS-CoV-2 infection. This study contributes to the growing body of evidence supporting the role of dietary factors in the management and prevention of infectious diseases and highlights the potential of targeted metabolomics in identifying prophylactic biomarkers.