The amount of calcium you need depends on your age. Adolescents need 1,300 milligrams of calcium a day. Adults need 1,000 milligrams up to age 50 and 1,200 milligrams after age 50.
The best way to figure out if you're getting enough calcium is to add up the amount of calcium in the foods you eat. Check the labels. For example, an 8-ounce glass of milk has nearly 300 milligrams of calcium, an 8-ounce cup of yogurt has between 250 and 400 milligrams of calcium, and 1.5 ounces of cheddar cheese has about 300 milligrams of calcium. Then compare what you're getting against the recommended amounts of calcium for your age group.
If you are not reaching the recommended minimums, talk to your doctor about ways you can boost your calcium levels, like changing your diet or taking supplements. But don't assume that more calcium is always better. Some studies have shown that women who take a lot of calcium supplements are at higher risk of developing kidney stones. The recommendation for the highest tolerable intake of daily calcium is 2,500 milligrams of calcium a day. More than this amount may increase your risk of kidney stones and other problems.