Serum 25-hydroxyvitamin D₃ levels and poor sleep quality in a Japanese population: the DOSANCO Health Study

The present cross-sectional study investigated the relationship between serum 25-hydroxyvitamin D₃ (25[OH]D₃) levels and the presence of poor sleep quality in a community-based Japanese adult population.

Poor sleep quality, defined as poor subjective sleep quality and/or use of sleep medications, was assessed using a self-administered questionnaire. The prevalence of poor sleep quality was compared among 512 Japanese participants aged 35-79 years, based on serum 25(OH)D₃ levels, which were determined using tandem mass spectrometry. A logistic regression model was used to calculate the odds ratios (ORs) for the presence of poor sleep quality in each group with the highest quartile of 25(OH)D₃ serving as the reference group.

Poor sleep quality was reported by 33.2% of the total study population. The prevalence of poor sleep quality was higher in the first quartile group (25[OH]D₃: 2.08-18.13 ng/mL) than in the second, third and fourth quartile groups (18.14-23.07 ng/mL, 23.08-28.32 ng/mL, and 28.33-78.83 ng/mL, respectively). The ORs for poor sleep quality were 1.86 (95% confidence interval, 1.08-3.20) for the first quartile group, 0.73 (0.41-1.29) for the second quartile group, and 0.73 (0.42-1.27) for the third quartile group after adjusting for age, sex, and sociodemographic, lifestyle, physical and environmental factors, while the ORs were 1.68 (0.96-2.95), 0.69 (0.39-1.24), and 0.65 (0.37-1.15) after further adjustment for overall health status and depression status.

The first quartile group of serum 25(OH)D₃ was associated with the presence of poor sleep quality.