24h Urine Calcium

Calcium is one of the most important minerals in your body. Most of your calcium is stored in your bones and teeth. About 1% of the calcium in your body is in your blood. If there's too much calcium in your blood, the extra calcium may be stored in your bones or passed in your urine and stool (poop).

Having just the right amount of calcium in your blood is necessary for your nerves, muscles, and heart to work properly. Calcium also helps your blood clot when needed, supports enzyme function, and is involved in bone metabolism. Your blood calcium levels are carefully controlled by your parathyroid glands, which are 4 pea-sized glands in your neck. If your blood calcium levels get too low, these glands make parathyroid hormones (PTH). The hormones are chemical messengers in your bloodstream that work to increase your blood calcium levels until they are normal again. Vitamin D, calcitonin, adrenal hormones, and other factors also help keep blood calcium in the right range.

Higher than normal calcium levels in urine may be a sign of many conditions, including: a kidney stone; overactive parathyroid glands (hyperparathyroidism); certain types of cancer, including cancer that spreads to the bones; bone disorders, including Paget's disease of bone and osteoporosis; sarcoidosis; vitamin D excess; or long periods of being unable to move around.

In adults, the risk of forming kidney stones tends to go up when 24-hour urine calcium is above roughly 250 mg in men and 200 mg in women, although your provider will look at the full picture of your urine results, not just one number.

Lower than normal calcium levels in urine may be a sign of many conditions, including: kidney disease; underactive parathyroid glands (hypoparathyroidism); too little vitamin D or magnesium; malabsorption disorder; and malnutrition.

If your calcium levels aren't normal, it doesn't always mean you have a medical condition that needs treatment. Urine calcium levels can be affected by your diet, certain supplements (such as taking too much vitamin D for a long period of time), and certain medicines, including antacids and some diuretics (water pills).

If you have questions about your results, talk with your provider.