In the search for the next weight-loss miracle, researchers focused the spotlight on calcium. Your body contains more calcium than any other mineral. You need adequate calcium to keep your bones strong, but some evidence suggests getting enough calcium in your diet might also play a role in maintaining a healthy weight. The idea that you could lose weight simply by drinking more milk or taking a calcium supplement is intriguing, but research has failed to support this theory.
Scientists have proposed two theories about calcium's link to weight loss. According to the U.S. Office of Dietary Supplements, one theory proposed that calcium might bind to small amounts of fat and prevent your body from absorbing it. Another theory held that putting more calcium in your body signaled the body that it didn't need to make as much vitamin D or parathyroid hormone, thus discouraging your body from storing fat.
A study in 2000 at the Osteoporosis Research Center of Creighton University looked at 780 women who participated in double-blind, placebo-controlled studies of calcium supplements. In four years, the women who took 1,000 mg of calcium a day weighed, on average, 3.5 lbs. less than women who did not take the calcium. Researchers concluded that the calcium was responsible for 3 percent of the body weight variance, or about 0.1 pounds. However, women who had a lower intake of calcium were 2.25 times more likely to be overweight than women who had greater calcium intake. Whether this is a function of lifestyle and dietary choices, or due to calcium, is unclear.
In 2003, researchers from the Department of Nutritional Sciences at Rutgers University gave 1,000 mg a day of calcium to 50 women, and a placebo to another 50, for 25 weeks. Both groups of women followed a low-calorie diet. At the end of the trial, no significant difference was observed between the weights and body fat compositions of the two groups. The placebo group lost 3 lbs., plus or minus 0.3 lbs., and the group that took calcium supplements lost 3.3 lbs., plus or minus 0.3 lbs. The U.S. Office of Dietary Supplements says most studies have demonstrated no connection between calcium and weight loss and that in studies in which a connection between calcium intake and lower weight appears evident, the study results are inconsistent and not well understood.
Whether or not it leads to weight loss, you might benefit from a calcium supplement if you don't get adequate calcium in your diet. Low-fat dairy products, fortified orange juice and dark green, leafy vegetables such as spinach are good dietary sources of calcium. The U.S. Office of Dietary Supplements recommends that adult women and men get 1,000 mg of calcium daily. This increases to 1,200 mg daily after age 50 for men and age 70 for women. If you are at risk for osteoporosis, your doctor might advise supplementation.