Calcium supplements don't prevent weight gain

Contrary to what some studies have suggested, taking calcium supplements may not help overweight adults avoid further weight gain.

Some studies in the past had found increasing calcium intake may help prevent weight gain. Both children and adults with low calcium intakes have been shown to have more body fat, while other studies have linked low-calcium diets to greater weight gain over time.

To test the hypothesis that calcium supplementation can prevent weight gain in persons who are overweight or obese, researchers recruited 340 overweight or obese American adults with an average age of 39 years through newspaper and radio advertisements. Half were randomly assigned to take 1,500 milligrams of calcium carbonate every day with meals for two years. The rest were given placebo capsules for comparison. At the outset, most participants were getting less than the recommended 1,200 milligrams of calcium per day.

After two years, no significant differences were found between the calcium and placebo groups in average weight, fat mass or waist size, all of which increased slightly in both groups.

In theory, calcium could help control weight for several reasons. For one, it combines with fatty acids in the intestines to form insoluble soaps that the body cannot absorb. In addition, low calcium levels in the body may cause more triglycerides (a blood fat) to be stored in fat cells.

However, the above findings suggest that calcium supplements have limited efficacy in preventing weight gain. However, some researchers believe there is something about dairy foods, not just calcium, that may affect metabolism and weight.