Association between dietary niacin intake and suicidal ideation: mediating role of C-reactive protein

While dietary niacin intake is acknowledged for its beneficial impact on mental health, the precise relationship between dietary niacin intake and suicidal ideation (SI) remains unclear. This study seeks to explore the potential association between the prevalence of SI and dietary niacin intake. In this study, the data of 26,224 American adults from NHANES were analyzed. To explore the association between dietary niacin intake and SI, as indicated by Item 9 of the Patient Health Questionnaire-9 (PHQ-9), restricted cubic spline, logistic regression, and stratified analyses were utilized. Furthermore, mediation analyses were performed to explore the role of C-reactive protein (CRP) in the association between SI and dietary niacin intake. Among the subjects, 970 (3.7%) of them reported experiencing SI. Logistic regression analyses demonstrate a significant inverse association between dietary niacin intake and the prevalence of SI, even after adjusting for potential confounding variables (OR = 0.86, 95% CI: 0.77, 0.96). Subgroup analyses indicate a more pronounced association between SI and dietary niacin intake in individuals with a history of hyperlipidemia. Additionally, a non-linear association and saturation effect were observed between dietary niacin intake and the prevalence of SI, characterized by an L-shaped curve with an inflection point at 26.78 mg/day. Mediation analysis reveales that 3.6% of this association was mediated by CRP. This study indicates an increased dietary niacin intake associated with a reduced prevalence of SI, underscoring the potential public health and clinical importance of dietary niacin intake.