Studies about vitamin D, bright light, and PMS:
Vitamin D Supplementation for Premenstrual Syndrome-Related Mood Disorders in Adolescents with Severe Hypovitaminosis D (2016)
Conclusion: In a randomized control trial involving 158 vitamin D-deficient teenage girls and young women, the girls given high doses of vitamin D adequate for correcting their deficiencies experienced significantly less severe PMS symptoms over the four-month period compared to the placebo group.
Conclusion: In a 6-month randomized control trial comparing the effects of 10,000 lx bright light with 500 lx placebo light on women with late luteal phase dysphoric disorder, it was found that bright light therapy (you know… like SUNLIGHT) was effective for significantly reducing PMS symptoms and improving mood.
Conclusion: This study tested the effect four months of daily light therapy sessions on 17 women with severe PMS. At the end of the study 12 of the women (71%) reported not even having PMS symptoms at all anymore and PMS symptoms for the entire group decreased by 76% “with clinically and statistically significant reductions for depression, anxiety, affective lability, irritability, poor concentration, fatigue, food cravings, bloating and breast pain.” The results obtained from light therapy in this study are superior to results from experiments with the SSRI antidepressant fluoxetine.