The Association Between Dietary Vitamin C and Sleep Disorders: A Cohort Study Based on UK Biobank

Objective: Approximately 30% of adults globally suffer from sleep disorders. However, there are few longitudinal studies on the association between dietary vitamin C and sleep disorders. This study aimed to investigate the association between dietary vitamin C intake and various types of sleep disorders, including sleep apnea and insomnia. Methods: We enrolled 68,221 participants from the UK Biobank. Dietary vitamin C intake was assessed using a 24 h dietary recall questionnaire. We employed a Cox regression model to assess the association between dietary vitamin C and sleep disorders and used restricted cubic spline models to investigate potential nonlinear relationships. Stratified and sensitivity analyses were also conducted to validate the findings. Results: The results indicated that vitamin C intake at the Q4 level (132.88-191.51 mg/d) was significantly associated with a reduced risk of sleep disorders, with an HR (95% CI) of 0.78 (0.65-0.94), and against sleep apnea, with an HR (95% CI) of 0.75 (0.62-0.92). The protective effect persisted significant in stratified analyses of men and those aged ≤ 60 years; the results were consistent in the sensitivity analyses. Conclusions: Our findings suggest that sufficient dietary vitamin C intake may help to prevent sleep disorders.