| Effect | Decrease |
| Values | Mean + SD. Placebo: before 35 ± 10, after 28 ± 8. Vitamin D: before 39 ± 8, after 21 ± 6 . |
| Trial Design | Randomized trial |
| Trial Length | 1-6 months |
| Number of Subjects | 44 |
| Sex | Female |
| Age Range | 18-29 |
In a randomized, double-blind, placebo-controlled trial, 44 women with premenstrual syndrome and vitamin d deficiency (serum 25(OH)D levels 10–30 ng/mL) were allocated to take placebo or 50,000 IU of vitamin d every 2 weeks for 4 months. After 4 months, there was a greater reduction in PMS symptoms in the vitamin D group, the difference between groups being statistically significant. The vitamin D group also saw a greater reduction in IL-10, IL-12, and a greater increase in total antioxidant capacity, all of which were statistically significant compared with placebo.
