Association between vitamin C in serum and trouble sleeping: evidence from NHANES 2017-2018

Background: Vitamin C is an important micronutrient for human. Assocision between vitamin C and trouble sleeping was less studied. Therefore, the purpose of this study was to investigate the possible link between vitamin C in serum and trouble sleeping. Methods The cross-sectional data was derived from the National Health Nutrition and Examination Survey (NHANES, 2017–2018). We used multivariate logistic regressions to examine the possible link between vitamin C in serum and trouble sleeping, and then a subgroup analysis was performed. Moreover, the non-linear relationship between vitamin C in serum and trouble sleeping was further detected using a restricted cubic spline(RCS) model. Results A total of 4277 participants were included in the study. After adjusting all potential confounders, the results of multivariate logistic regression showed the signifcant association between vitamin C in serum and trouble sleeping( OR  = 0.790; 95%CI  = 0.680 ~ 0.918). The signifcant association was also found in female( OR  = 0.694; 95%CI  = 0.569 ~ 0.845), age ≤ 65 years( OR  = 0.746; 95%CI  = 0.616 ~ 0.904), other race( OR  = 0.557; 95%CI  = 0.369 ~ 0.841) and in participants with diabetes( OR  = 0.692; 95%CI  = 0.503 ~ 0.951) or high cholesterol level( OR  = 0.728; 95%CI  = 0.579 ~ 0.916). In addition, the RCS model demonstrated the signifcant non-linear relationship between vitamin C in serum and trouble sleeping( P value of nonlinear = 0.0127). Conclusions The cross-sectional population based study indicates that vitamin C in serum is a protective factor for trouble sleeping. Nevertheless, more studys are needed to further confrm our fndings.