Shaoxia Wang,1– 3 Xiang Zhang,1 Yanru Ding,1 Yanrong Wang,2,4 Chujun Wu,2,4 Shihao Lu,1,2 Jianqun Fang2,4 

1School of First Clinical, Ningxia Medical University, Yinchuan, Ningxia, 750004, People’s Republic of China; 2Institute of Medical Sciences, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, 750004, People’s Republic of China; 3Ningxia Civil Affairs Department Minkang Hospital, Yinchuan, Ningxia, 750001, People’s Republic of China; 4Mental Health Center, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, 750004, People’s Republic of China

Correspondence: Jianqun Fang, Institute of Medical Sciences, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, 750004, People’s Republic of China, Email fjq7887215@163.com

Objective: Vitamin B12 is crucial for neurological functions and linked to various psychiatric disorders. Given its importance, this study explores the impact of vitamin B12 deficiency on sleep quality in Obsessive-Compulsive Disorder (OCD) patients, while also examining folate and homocysteine levels to explore their potential interactions with OCD symptoms and sleep quality.
Methods: This cross-sectional study included 52 patients with OCD and 42 healthy controls. Serum levels of vitamin B12, homocysteine, and folate were measured. The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Pittsburgh Sleep Quality Index (PSQI) were used to evaluate the severity of OCD symptoms and the quality of sleep, respectively. Correlations and mediating effects between these variables were also assessed.
Results: Vitamin B12 levels were significantly lower in OCD patients compared to healthy controls, and scores for sleep disturbances were significantly higher in the OCD group. No significant differences were observed in the levels of folate and homocysteine between the groups. Correlation analysis indicated that lower levels of vitamin B12 were significantly associated with more severe OCD symptoms and poorer sleep quality. Further mediation analysis suggested that low levels of vitamin B12 partially mediated the relationship between OCD symptoms and sleep disturbances.
Conclusion: Lower levels of vitamin B12 not only affect sleep quality but also partially mediate the impact of OCD symptoms on sleep disturbances. Future clinical attention to vitamin B12 deficiency is crucial for further assessing the relationship between OCD symptoms and sleep disorders.

Keywords: obsessive-compulsive disorder, sleep disturbances, vitamin b12, mediating effects