Calcium, vitamin D may help prevent PMS

Among thousands of 27- to 44-year-old women involved in the ongoing Nurses' Health Study II, those who consumed the most vitamin D and calcium-rich foods had the lowest risk of Premenstrual syndrome (PMS), study suggests.

"Our findings, together with those from several small randomized trials that found calcium supplements to be effective in treating PMS, suggest that a high intake of calcium and vitamin D may reduce the risk of PMS," study author Dr. Elizabeth R. Bertone-Johnson and her colleagues write in the Archives of Internal Medicine.

As many as nine of every ten women experience irritability, fatigue, stomach cramps, or some other type of mood or physical symptom before the onset of their monthly period. For most women, symptoms are mild, but as many as 20 percent of women - those diagnosed with PMS - have symptoms so severe that they interfere with their daily activities and relationships.

Research has shown that women with PMS who supplement their diets with calcium experience premenstrual symptoms less frequently and less severely than those with lower calcium intakes. However, such research did not determine whether a high calcium intake can actually prevent PMS, or the extent to which vitamin D intake may be associated with the condition.

To investigate, Bertone-Johnson, of the University of Massachusetts, and her team analyzed information collected from women who had no PMS symptoms at the start of the study in 1991. During the course of the study, 1,057 women developed the disorder while 1,968 women remained free of the condition or had only minimal symptoms.

The researchers gave the women a food frequency questionnaire in 1991, 1995 and 1999 to evaluate their intake of milk, yogurt, cheese, spinach and other calcium and vitamin D-rich foods, as well as whether they supplemented their diet with calcium-containing antacids, vitamin D, or multivitamins.

The team found that women whose diets included the largest amounts of vitamin D and calcium-rich foods, respectively, were 41 percent and 30 percent less likely to develop PMS during the 10-year study period.

These women consumed about 1,200 milligrams of calcium and 400 IU of vitamin D from food sources, the report indicates, which is consistent with the recommendations of the United States Department of Agriculture.

Despite these "provocative" study findings, Bertone-Johnson said it is "premature to recommend" that women increase their intake of calcium and vitamin D to guard against developing PMS.

"Additional studies are warranted and needed to confirm our findings," she said, adding that women who suspect they may be at risk for PMS based on their family history should discuss the findings with their physicians.