Premenstrual syndrome (PMS) begins during adolescence and presents itself with a wide variety of symptoms, including mood swings, abdominal bloating, anxiety, irritability, depression and fatigue. Normally, these symptoms are of mild intensity. However, in up to 20% of women, the symptoms become severe enough to interfere with every day activities and relationships.
Researchers found that calcium and vitamin D levels fluctuate during the menstrual cycle. In addition, studies have shown vitamin D levels are related to anxiety and depression. Based on these observations, researchers conducted a study to assess whether vitamin D supplementation reduces the severity of mood disorders associated with PMS in young women.
A total of 158 young women, ages 15-21 years old with severe PMS related symptoms and extremely low vitamin D status (< 10 ng/ml), were randomly assigned to the placebo group or vitamin D group. The vitamin D group received an initial dose of 200,000 IU of vitamin D followed by 25,000 IU every two weeks for the next four months. The placebo group received a dummy pill at the same time intervals.
Vitamin D levels were measured at baseline and each subsequent month. The researchers compared the severity of PMS symptoms experienced at baseline to the severity of symptoms after four months of treatment.
Here is what they found:
- The vitamin D group achieved vitamin D sufficiency (35-60 ng/ml) after the first month and remained stable throughout the entire study.
- The anxiety and irritability scores significantly decreased in the vitamin D group (p < 0.001).
- Crying easily and sadness significantly decreased in the vitamin D group (p < 0.001).
- Disturbed relationships significantly decreased in the vitamin D group (p < 0.001).
- No significant changes in the frequency of adverse events, such as nausea and constipation, occurred in either group.
- The placebo group did not experience any significant changes in the severity of symptoms.
The researchers concluded,
“Vitamin D therapy can be suggested as a safe, effective and convenient method for reducing the intensity of PMS mood disorders, and consequently improve the quality of life in young women with severe hypovitaminosis D and concomitant mood disorders associated to PMS.”
This study possessed many strengths. The study was a randomized controlled trial (RCT), the gold standard of research. The sample population consisted of severely vitamin D deficient patients who suffer from severe PMS symptoms, allowing researchers to better evaluate the benefits of vitamin D for PMS. The researchers measured vitamin D levels throughout the entire study duration, ensuring that the vitamin D group achieved sufficient levels. The main limitation worth acknowledging is the somewhat small sample size. Randomized controlled trials with larger sample sizes should be conducted to see whether these results are replicable.
Tovey, A. & Cannell, JJ. Does vitamin D help treat PMS symptoms? The Vitamin D Council Blog & Newsletter, January, 2016.