A calcium and vitamin D supplement appeared to decrease lipid intake and may be an adjunct to weight loss with a low-calorie diet in women who usually eat a very low-calcium diet, a study with 13 women showed.
“To our knowledge, the present study is the first to report in human subjects a possible association between calcium and vitamin D supplementation body, fat, and variables influenced by appetite control,” wrote Geneviève C. Major and her associates from the department of social and preventive medicine, Laval University, Quebec City.
The results suggest that “a calcium plus vitamin D supplement might be necessary for people with very low-calcium intake to achieve a successful weight loss,” they added (Br. J. Nutr. 2009;101:659–63).
“Our hypothesis is that the brain can detect the lack of calcium and seeks to compensate by spurring food intake, which obviously works against the goals of any weight-loss program,” said Angelo Tremblay, Ph.D., senior researcher on the study and professor of social and preventive medicine at Laval University, in a statement. “Sufficient calcium intake seems to stifle the desire to eat more.”
The Laval researchers screened 234 women who lived in the Quebec City area, and enrolled 84 who were overweight or obese and had a typical calcium intake of less than 800 mg/day. All were placed on a weight-loss diet of 2,900 kJ/day, and were randomized to receive a calcium and vitamin D supplement or placebo.
The supplement, taken twice daily, contained 600 mg of elemental calcium and 5 mcg vitamin D. Nineteen women dropped out after enrollment, and another two were excluded from the final analysis because of significant deviations from the study protocol. This left 63 women available for analysis. Their average age was 43, and their average body mass index at baseline was 32 kg/m
After 15 weeks, weight and fat loss were similar for the supplement and control participants. But a subgroup analysis showed a treatment effect in 13 people who entered the study with a daily calcium intake of 600 mg/day or less.
Among the seven people in this subgroup who received the calcium and vitamin D supplement, the average change in body mass index at the end of the study was a loss of 2.2 kg/m
All these changes were statistically significant, compared with the six people who entered the study consuming 600 mg/day or less of calcium and were assigned to the placebo group. In this group, body mass index dropped by an average of 0.5 kg/m
Providing adequate calcium intake with a supplement could help a weight-reduction diet succeed, the researchers said.