The results of this relatively small randomized controlled trial suggest that vitamin D supplementation of severely vitamin D-deficient teenage girls with mood disorders related to premenstrual syndrome will significantly improve their symptoms. I wish they had elaborated on patient details so I could interpret the magnitude of the benefit.
Source: Tartagni M, Cicinelli MV, Tartagni MV, et al. Vitamin D supplementation on premenstrual syndrome-related mood disorders in adolescents with severe hypovitaminosis D [published online ahead of print December 24, 2015 - In Press]. JPediatr Adolesc Gynecol. doi:10.1016/j.jpag.2015.12.006. See AAP Grand Rounds commentary by Dr. Joy Weydert (subscription required).
PICO Question: In adolescents with severe premenstrual syndrome (PMS) and vitamin D deficiency, does vitamin D supplementation reduce mood disorders associated with PMS?
Question type: Intervention
Study design: Randomized, controlled trial
This study builds on a growing body of evidence linking hypovitaminosis D and low blood concentrations of calcium to premenstrual syndrome (PMS) symptoms. The investigators found, among a group of 15-21 year old women with PMS and severe vitamin D deficiency (< 10 ng/mL), that vitamin D supplementation, compared to placebo administered in a blinded fashion, improved mean group scores for multiple measures of PMS-associated mood disorders. All of the women in the vitamin D group achieved vitamin D levels in the normal range within a month of initiating treatment.
What I felt was missing from the report is a more detailed description of how many individual patients had significant symptom improvement in the vitamin D compared to placebo groups. It's one thing to report group mean scores on the various symptom scales, but a better approach would be to define what score improvement constitutes a significant benefit to an individual, and then tell us how many vitamin D and how many placebo recipients achieved this goal. That's a more practical measure of the magnitude of the therapeutic benefit and allows us to calculate a number needed to treat. It avoids overstating a benefit where a few study participants might achieve a very large change in symptom score, but the majority of participants have little change. The study authors themselves stated "....although beneficial for a significant number of patients [without telling us how many patients], replacement of vitamin D did not ameliorate mood symptoms in all patients...." in the vitamin D group. Why not just tell us how many benefited, and also how many in the placebo group improved?
On the basis of this study and others, it may be reasonable to prescribe vitamin D to severely deficient young women, not only for PMS symptoms but for other health benefits. Whether supplementation is beneficial for women with less severe, or even low normal, vitamin D levels should be the subject of additional studies.
