Letter: sleep and psychological disorders in patients with inflammatory bowel diseases; another potential role of vitamin D deficiency

Abstract

We read with great interest the comprehensive review study of Mouli and Ananthakrishnan.1 The authors have evaluated and discussed current evidence regarding the roles of vitamin D deficiency in the pathogenesis and progression of inflammatory bowel disease (IBD). In this regard, different cellular and molecular mechanisms are discussed in this review. However, as mentioned by the authors, there is a strong role for environmental factors in the pathogenesis and progression of IBD. There is growing evidence that psychological factors, including psychological stress and depression, are influential in the pathogenesis and clinical course of IBD.2, 3 Growing evidence also indicates the importance of sleep disorders in the clinical course of IBD. It has been shown that sleep disturbance increases the risk of disease flares in patients.4-6 It is therefore interesting that vitamin D deficiency has been shown to play a role in both psychological7 and sleep disorders8 in non-IBD populations, although the underlying mechanisms are still unknown. There is no study till now evaluating the effects of vitamin D deficiency on psychological health or sleep quality in IBD patients. Although several factors can affect psychological health and sleep quality in IBD patients including demographic- and disease-related factors,2, 4 a role for vitamin D deficiency is also plausible. Therefore, the ‘optimal role of vitamin D supplementation as a therapeutic modality in patients with IBD’ is not only the induction and maintenance of remission as mentioned by Mouli and Ananthakrishnan1 but may also include treatment of psychological and sleep disorders in IBD patients. These issues should be added to the remaining unanswered questions regarding the role of vitamin D in IBD, and warrant evaluation in future studies. Declaration of personal and funding interests: None.