Taking calcium supplements is encouraged for women even before the onset of menopause that causes bone loss. In an article in the American Journal of Clinical Nutrition, Chinese researchers reported an additional benefit of increasing one’s intake of the bone-loving mineral: Additional calcium can help reduce weight and prevent the onset of obesity for premenopausal women.
More than 30 years ago, researchers first discovered an inverse relationship between calcium intake and body weight. Several studies into the matter found that calcium supplements could increase the amount of weight lost during excretion and oxidation of fat, as well as improving the effectiveness of insulin.
However, succeeding systematic reviews and meta-analyses cannot agree on whether or not calcium supplementation significantly affected weight loss. Some studies looked at randomized controlled trials and reported that there is no evidence to support it.
Others noted a slight correlation but warned that the matter remained unclear. Still, others vouched for supplementation being able to reduce weight and increase the loss of fat over long periods of time. (Related: Calcium decreases the risk of cardiovascular disease in women.)
Can increasing calcium help reduce body weight?
A research team from Beijing’s Capital Medical University (CMU) undertook a meta-analysis of these studies. They believed that possible effects of age, body mass index (BMI), the time when the subjects took calcium supplements, and sex could have accounted for the differences in opinion.
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The researchers sought to update the body of evidence regarding the part played by calcium in body weight and obesity. They wanted to know if meeting the recommended intake of 1000 milligrams of calcium each day for at least 12 weeks could reduce weight.
In addition, they divided the participants into a number of subgroups. This was to find out if certain criteria could have affected the outcomes of the trial.
To this end, they canvassed the databases of the China National Knowledge Infrastructure, EMBASE, PubMed, and Web of Knowledge. The researchers limited themselves to studies published during a period from January 1994 to March 2016.
They included research that used randomized controlled trials, as well as longitudinal studies about calcium supplements. Their search came up with 33 studies that fit their criteria. The total number of participants in those papers amounted to 4,733.
Using a software program with a random-effects model and a fixed-effects model, they analyzed the results of each study.
Calcium supplements help premenopausal women (and kids and adult men) lose weight
In their meta-analysis, the CMU researchers did not come across notable weight changes between the calcium supplementation group and the control group. They did find negative correlations in children, adolescents, adult men, premenopausal women, and older women.
In short, taking fewer calcium supplements exposed the subjects to greater risks of weight gain and obesity. Postmenopausal women were the only group that did not display negative correlations.
Once they considered BMI, the researchers reported finding negative correlations in subjects with normal body-mass indexes. Meanwhile, participants who were already obese or overweight, to begin with, did not show any such associations.
Moreover, the researchers found that it did not matter how long the calcium intervention period lasted. There were no shifts in weight changes in the group that took calcium supplements for less than six months or the group that supplemented for at least six months or more.
Based on the results of their meta-analysis, the CMU researchers concluded that calcium supplementation could reduce body weight in certain groups of people: Those with normal BMI, as well as children, adolescents, adult males, and premenopausal women.
You can find more articles on the benefits of supplementing with calcium or other minerals at Nutrients.
Sources include:
NCBI.NLM.NIH.gov
Academic.OUP