Korean J Fam Pract.  2022 Feb;12(1):41-47. 10.21215/kjfp.2022.12.1.41.

Association between Serum Vitamin D Level and Sleep Quality in Shift-Workers

• Kim S
• Choi J
• Min J
• Park H
• Park KH
• Cheung B
• Lee S

• KMID: 2526374
• DOI: http://doi.org/10.21215/kjfp.2022.12.1.41

Abstract

Background
Many studies have reported a correlation between serum vitamin D (25[OH]D) level and sleep problems. This study aimed to evaluate the relation, if any, between the serum vitamin D level and sleep quality in shift workers.
Methods
Serum vitamin D levels and Insomnia Severity Index (ISI) scores for shift workers in Seoul Medical Center were retrieved from the annual physical exam records from 2019 to 2020. To compare the levels and scores across sexes and study years, independent t-test and paired t-test were used for the former and the latter, respectively. We used K-ISI score to evaluate sleep quality.
Results
Altogether, 260 eligible annual physical exam records of 130 shift workers in a medical center were collected during the study period. In logistic regression analysis, the odds of impaired sleep quality was 0.98 times that of a unit increase in serum vitamin D level when all other study variables or selected variables (age, sex, body mass index, smoking and alcohol history, and nutrition supplement intake) were controlled; however, no statistical significance was found.
Conclusion
Sleep quality may be associated with vitamin D level in shift workers. However, further research on this association is needed.

Keyword

Vitamin D; Vitamin D Deficiency; Sleep; Sleep Wake Disorders