Preventing PMS: vitamin and mineral let women avoid syndrome.

Ample calcium and vitamin O in the diet prevent premenstrual syndrome in some women, a new study suggests.

Each month, as menstruation approaches and begins, most women experience at least mild symptoms such as depression, irritability, discomfort, or fatigue. In 8 to 20 percent of premenopausal women, these problems are severe enough to warrant a diagnosis of premenstrual syndrome, or PMS. That disorder is defined by symptoms that interfere with normal activities and relationships.

Studies have shown that calcium supplements, as well as antidepressant medications known as selective serotonin reuptake inhibitors (SN: 10/7/00, p. 231), can ease PMS.

No relationship was obvious between calcium consumption and risk of developing the disorder among women who don't have PMS, says epidemiologist Elizabeth R. Bertone-Johnson of the University of Massachusetts in Amherst.

To investigate the possibility of a link, she and her colleagues periodically contacted about 3,000 female nurses who in 1991 were free of PMS. They were, on average, 35 years old. Then, every 2 to 4 years, the researchers recorded how often each woman reported eating various foods and whether she had developed PMS. By 2001, 1,057 women reported having the disorder.

Volunteers who got the most calcium in their diets were only 70 percent as likely to develop PMS as were those who took in the least amount of the mineral. Variation in vitamin D consumption accounted for a similar difference, the researchers report in the June 13 Archives of Internal Medicine. Vitamin D helps the body absorb calcium.

The researchers also analyzed consumption of milk, which is rich in both nutrients. PMS was only 54 percent as likely to arise in women who had four or more daily servings of skim or low-fat milk as it was in women who drank milk no more than once a week, the researchers report. Whole milk offered no apparent benefit, perhaps because milk fats offset the nutrients' benefits, Bertone-Johnson says.

Too few of the volunteers took nutritional supplements containing calcium or vitamin D to show an effect from such pills, Bertone-Johnson says. But since calcium supplements can relieve PMS, pills containing either nutrient can probably prevent the condition too she says.

Most young women don't take supplemental calcium or vitamin D, but "maybe they should," says Susan Thys-Jacobs of St. Luke's-Roosevelt Hospital Center in New York City. "Women should be taking at least 1,000 milligrams of calcium and at least 1,000 units of vitamin D daily, and few get that much from diet alone," she says.