Is There an Association Between Serum Levels of Vitamin D, Sleep Quantity, and Sleep Quality in Health Care Workers? Data From the Azar Cohort Study

The association between serum vitamin D levels and sleep quantity and quality was evaluated in this cross-sectional study, which was conducted on 1428 health care workers enrolled in the health care worker cohort study. Demographic characteristics, anthropometry, blood pressure, sleep quality using the Pittsburgh Sleep Questionnaire Inventory (PSQI), and serum levels of 25(OH) vitamin D were noted. The prevalence of vitamin D insufficiency and deficiency in health care workers was 26.6% and 49.5%, respectively. Generally, 90.3% of the participants rated their sleep as fairly good or very good and the mean PSQI score was 4.69 +/- 2.5. Only a small number of participants had sleep efficiency less than 65% (2.3%). There was no significant association between vitamin D levels and PSQI components (P > .05), possibly because most participants had good sleep quality.