Calcium is the most abundant mineral in the human body. Average healthy males have about two and a half to three pounds of calcium while females have about two pounds. Approximately 99 percent of calcium is present in the bones and teeth, which leaves only about one percent in cells and body fluids. While the most important function of calcium involves the maintenance of skeletal health, the small percentage of calcium outside the bones is used to maintain a variety of vital body functions. Calcium may initiate muscle contractions. For this reason it plays a vital role in maintaining a healthy heartbeat. It is also involved in the body's blood clotting process. On the cellular level, calcium regulates the passage of nutrients and wastes through cell membranes. It is also involved in the regulation of various enzymes that control muscle contraction, fat digestion, and metabolism.

Everyone knows what it means to be overweight. From early age on, children can tell the difference between "fat" and "thin" people. They also get the clear message that fat people are apt to be less popular. Body weight is one of the most basic issues of human life. Self-esteem, acceptance among peers and perhaps lifelong success or failure are all tied to our physical appearance. Medically speaking, not all overweight people are obese. Obesity is defined as weight that exceeds 15 percent of normal weight for height and body type. "Morbid" obesity exceeds 20 percent of optimum weight. An obese or overweight person is at high risk for a number of serious health problems, including heart disease, high blood pressure, stroke, varicose veins, dementia, psychological stress, depression, osteoarthritis, high cholesterol, and diabetes.

A recent study has found that calcium plus vitamin D supplementation can increase weight loss in people with calcium deficiency. The randomized, double-blind placebo-controlled study included 63 overweight or obese women who reported a daily intake of less than 800 mg of calcium. At the end of the study, the researchers did not find a statistically significant increase in fat loss with the calcium plus vitamin D supplementation. However, when they further limited their analysis to women with very low-calcium intakes, defined as less that 600 milligrams, they found that weight loss was almost 6 kg (13 pounds), compared to 1 kg (2.2 pounds) for women in the control group. They conclude that sufficient calcium consumption is therefore important to ensure the success of any weight loss program.¹ 

¹ Major GC, Alarie FP, Doré J, et al. Calcium plus vitamin D supplementation and fat mass loss in female very low-calcium consumers: potential link with a calcium-specific appetite control. Br J Nutr. Mar2009;101(5):659-63.