| Effect | Increase |
| Values | (hours. Mean and SD. Placebo: before 5.22 ± 1.54, after 5.21 ± 1.44. Vitamin D: before 5.83 ± 1.15, after 6.50 ± 1.49. |
| Trial Design | Randomized trial |
| Trial Length | 1-6 months |
| Number of Subjects | 93 |
| Sex | Both Genders |
| Age Range | 18-29, 30-44, 45-64 |
In a randomized, double-blind, placebo-controlled trial, 93 participants with poor sleep quality were allocated to take either 200,000 IU of vitamin D or placebo every two weeks for 8 weeks. The baseline serum 25 (OH)D level was 25.00 ± 8.95 ng/ml in the vitamin D group and 27.60 ± 8.30 in the placebo group. At the end of the study, the vitamin D group saw an increase to 37.69 ± 12.25, while the placebo group didn't see a notable change.
Sleep quality, according to the PSQI was improved more in the vitamin d group, the difference being statistically significant. Sleep duration increased, sleep latency decreased, and sleep deficiency increased more in the vitamin D group than the placebo group, the differences being statistically significant, though adjustment for potential confounding factors resulted in the-value for sleep efficiency being p=0.082. While day time dysfunction decreased in the vitamin D group, the difference wasn't statistically significant.
