Postmenopausal women who take calcium and vitamin D supplements may gain less weight than those who do not, although the overall effect is small, according to a report in the May 14 issue of Archives of Internal Medicine. The benefit is greater in those who had not previously been getting the daily recommended amount of 1,200 milligrams of calcium.
"Because weight loss or prevention of weight gain is likely to have significant health benefits for middle-aged women, early to middle menopause may be a critical period of life in which to slow the trajectory of weight gain," said the authors, including Drs. Marian Neuhouser and Andrea LaCroix of the Public Health Sciences Division. LaCroix is a co-principal investigator for the Women's Health Initiative Clinical Coordinating Center, which is based at the Hutchinson Center.
Some evidence suggests that calcium and vitamin D may play a role in weight management. These nutrients may stimulate the breakdown of fat cells and suppress the development of new ones.
The researchers studied 36,282 postmenopausal women age 50 to 79 for about seven years who were enrolled in the WHI clinical trial. The women were randomly assigned to receive a dose of 1,000 milligrams of calcium plus 400 international units of vitamin D or a placebo.
Among women who were getting less than the recommended amount of calcium daily before the study, those who took the supplements weighed an average of 0.42 pounds less than those who did not. After three years, when compared to women taking the placebo, these women had a lower risk of gaining weight in both small amounts (2.2 to 6.6 pounds) and moderate amounts (more than 6.6 pounds) and had a higher likelihood of maintaining a stable weight (within 2.2 pounds of starting weight) or losing weight (more than 2.2 pounds).
"Prevention of weight gain is an important public-health goal, and caloric restriction and daily physical activity should still be considered the basic tenets of weight management," the authors said, and they urged further research to address the effect of calcium supplementation combined with caloric restriction and exercise on weight gain prevention.
The National Heart, Lung, and Blood Institute and the Department of Health and Human Services supported the study. GlaxoSmithKline Consumer Healthcare supplied the study medications.
[Adapted from a JAMA/Archives of Internal Medicine news release.]