Calcium is an element that's important for maintaining a healthy body. Calcium deficiency can cause stunted development of bones and teeth. Blood clotting and muscle contraction also are critical functions of calcium. A lack of vitamin D, which is needed for calcium's absorption and use, can have a similar effect. The National Institutes of Health sets standards for optimal calcium intake to help prevent or postpone a bone disease called 'osteoporosis', which especially occurs in post-menopausal women. The dairy industry, and even some antacid manufacturers, have used osteoporosis as a marketing tool, but in countries where dairy products are highly consumed, there actually are more cases of osteoporosis than in other countries. Some researchers believe that the real cause of osteoporosis in the U-S is not insufficient calcium intake, but too much excretion of calcium in the urine. Diets high in animal protein can cause more calcium to be lost through excretion, and this may be the actual cause of bone disease. Although most people in China, for example, consume no dairy products and obtain their calcium from vegetables, osteoporosis is uncommon there, even though the Chinese consume only half the calcium as Americans. Other sources of calcium besides dairy include green vegetables, such as collard greens, broccoli, and kale, as well as dried beans and peas. If you do eat dairy products, try to stick to nonfat. Milk rates second only to beef as the largest source of saturated fat in the American diet. Whole milk is 50 percent fat, and milk labeled 'low-fat' or 'two percent fat' milk is actually 38 percent fat.