Senior Women: Calcium with Vitamin D May Prevent Weight Gain
By Jeremy Appleton, ND, CNS
Women who don’t get enough calcium may get an unexpected benefit from calcium supplements: their weight loss efforts might be improved. A new study found that postmenopausal women between ages 50 and 79 were slightly, but consistently, better able to prevent weight gain than women who did not take the supplements.
According to the Centers for Disease Control and Prevention’s Behavioral Risk Factor Surveillance System, the proportion of obese women between ages 50 and 79 increased by nearly 50% during the 1990s; more recent reports show those rates beginning to stabilize. Being overweight in this age group raises the risk of coronary artery disease, hypertension, cancer, diabetes, gallstones, and other conditions.
“Some evidence exists that calcium and vitamin D and foods rich in these nutrients may have a role in effective weight management,” said Bette Caan, DrPH, a senior research scientist at the Division of Research, Kaiser Permanente Northern California and lead author of the new study. “The effect we observed was primarily for women whose total calcium intakes were lower than 1,200 mg per day.”
Dr. Caan and colleagues enlisted 36,282 postmenopausal women who were already enrolled in the dietary modification and/or hormone therapy arms of the Women’s Health Initiative clinical trial. At their first or second annual visit, women were randomly assigned to receive 1,000 mg of elemental calcium plus 400 IU of vitamin D or placebo daily. Change in body weight was measured annually for an average of seven years.
After three years of follow-up, women who got less than 1,200 mg of calcium daily at the start of the study who then supplemented with the calcium–vitamin D combination were 11% less likely to experience small weight gains (2.2 to 6.6 pounds) and 11% less likely to gain moderate amounts of weight (more than 6.6 pounds) compared with women who received placebo.
How calcium and vitamin D might help weight loss is still unclear. The two nutrients work together to regulate fat metabolism inside fat cells by stimulating fat breakdown and suppressing the synthesis of new fat. Calcium may also decrease the absorption of dietary fatty acids by forming “soaps” in the intestine and increasing elimination of fat in the feces.
Weight loss and prevention of weight gain can have significant health benefits for middle-aged women. But these benefits are not going to come from supplements alone. “Our findings do not alter current dietary recommendations,” said Dr. Caan. “Caloric restriction and daily physical activity should still be considered the basic tenets of weight management.”
(Arch Intern Med 2007;167:893–902)
Jeremy Appleton, ND, CNS, is a licensed naturopathic physician, certified nutrition specialist, and published author. Dr. Appleton was the Nutrition Department Chair at the National College of Naturopathic Medicine, has served on the faculty at Bastyr University of Natural Health Sciences, and is a former Healthnotes Senior Science Editor and a founding contributor to Healthnotes Newswire. He has worked extensively in scientific and regulatory affairs in the supplement industry and is now a consultant through his company Praxis Natural Products Consulting and Wellness Services.
