Now there's yet another reason for women to get plenty of calcium and vitamin D. The bone-building nutrients may prevent PMS.
PMS — premenstrual syndrome — is a collection of symptoms that come between ovulation and a woman's menstrual period. Symptoms include depression, irritability, fatigue, abdominal cramps, breast tenderness, and headaches. To qualify as PMS, the symptoms must be severe enough to interfere with normal life activities.
There are various ways to treat PMS, but no way to prevent it. Now a strong clue comes from University of Massachusetts researcher Elizabeth R. Bertone-Johnson, ScD, and her Harvard University colleagues. The researchers analyzed data collected over 10 years from nurses 27-44 years old participating in a long-term health study — including more than 1,000 women with PMS.
"We found women with high intakes of both calcium and vitamin D did have significantly reduced PMS risk," Bertone-Johnson tells WebMD. "Those who ate about four servings a day of low-fat dairy or yogurt or fortified orange juice had a 40 percent lower risk of PMS than those who did not. That is about 1,200 milligrams of calcium or 400 international units (IU) of vitamin D each day."
The findings appear in the June 13 issue of Archives of Internal Medicine.
Read Web MD's "Winning the War on PMS."
Women Not Getting Enough Calcium, Vitamin D
The recommended daily dose of vitamin D is 400 IU. Recommendations for calcium for adult women vary by age:
—Women 19 to 50 years old need 1,000 milligrams of calcium daily.
—Women 51 and over need 1,200 milligrams of calcium daily.
Women badly need this much calcium and vitamin D, says gynecologist Stephen Bashuk, MD, of Emory University.
"Women in the 18-30 age group at risk for PMS are in the prime of their bone mineralization years," Bashuk tells WebMD. "Every woman of childbearing age should be on calcium for her bones. Every women needs to be doing this to build up bones so she has less chance of dangerous fractures in her later years."
The women in Bertone-Johnson's study were all nurses. Yet only one in five was getting close to the recommended amount of calcium and vitamin D in her diet. Few were taking calcium supplements, so the study does not specifically address the issue of whether calcium and vitamin D supplements are needed. Yet Bashuk says the study gives women yet another reason to make sure they get enough calcium.
"What this study says is that if you take an 18-year-old woman without PMS — who has a 20 percent lifetime chance of getting it — if she takes her calcium she has less chance of getting PMS," Bashuk says.
"Whether to take calcium is a no-brainer. And if you get a side benefit that it may prevent PMS, that would be a wonderful thing. I certainly would recommend if a woman has PMS, and doesn't take calcium or doesn't have a good dairy intake, it is not an unreasonable thing for her to go on calcium supplements and see if it helps."
Read Web MD's "Vitamin D + Calcium = Good Bones."
Best Calcium Sources
To give you an idea of how much calcium is in some calcium-rich foods, here are some examples:
—1 cup of milk
—1/2 cup of broccoli
—1/2 cup of spinach
— 1.5 ounces of cheddar cheese
— 8 ounces of low-fat yogurt
— 1 cup of calcium-fortified orange juice
Bertone-Johnson and Bashuk both note that a study of this kind does not prove that calcium or vitamin D really prevents PMS. Only a clinical trial can do that. In the meantime, women may wish to consult their doctors about whether — and how — to get more calcium and vitamin D.
"I think it is something women can talk about with their doctors, whether they are thinking about increasing calcium and vitamin D to prevent PMS or to strengthen their bones," Bertone-Johnson says. "It is premature to suggest this is going to be the magic bullet to prevent PMS. But it is something women, after talking with their doctors, may want to incorporate into their diets."
Read Web MD's "Women's Top 5 Health Concerns."
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SOURCES: Bertone-Johnson, E. Archives of Internal Medicine, June 13, 2005; vol 165: pp 1246-1252. Elizabeth R. Bertone-Johnson, ScD, assistant professor of epidemiology, University of Massachusetts, Amherst. Stephen Bashuk, MD, assistant professor of obstetrics and gynecology, Emory University, Atlanta.