Most kidney stones include a combination of calcium and substances called oxalates, organic acids that occur naturally in plant foods. If you have kidney stones, you may have too much calcium in your urine, a condition doctors call hypercalciuria, according to Johns Hopkins Medicine. However, taking the amount of calcium recommended for your age and gender shouldn't raise your risk for kidney stones.
Kidney Stones and Hypercalciuria
The hypercalciuria that often causes kidney stones can occur for several reasons, according to Johns Hopkins Medicine. For example, your digestive tract might be absorbing too much calcium from your food, or you might be converting too much calcium from your bones. It's also possible that your kidneys are failing to properly regulate the amount of calcium they release into your urine. It's also possible that you've formed calcium oxalate kidney stones because of an excess of oxalate, not calcium. Excess oxalate in your urine can stem from inflammatory bowel disease or prior surgery on your digestive system, two potential causes that you should discuss with your physician.
Calcium Restriction
Some cases of hypercalciuria -- but not all -- can be reversed by cutting the amount of calcium in your diet. Your physician will tell you if you should try to stop kidney stone formation by restricting the calcium in your diet. If you need to do so, you'll need to keep your calcium intake carefully in a narrow range, most likely between 800 and 1,200 mg per day, depending on your age and sex, according to Jackson Gastroenterology in Camp Hill, Pennsylvania. You may also need to restrict your consumption of high-oxalate foods, which include spinach, strawberries, rhubarb, wheat bran and chocolate.
Foods with Calcium
Foods that contain calcium include dairy products such as milk, cheese, ice cream and yogurt. In addition, broccoli, instant oatmeal and pizza also contain calcium, and some orange juice products are calcium fortified. Most multivitamins contain calcium as well. If you need to restrict your calcium intake because of kidney stones, you may find it's easy to reach or even exceed your daily allotment. For example, 1/2 a cup of macaroni and cheese contains about 200 mg of calcium, and 1 oz. of cheese contains 200 to 300 mg. Oatmeal contains more than 160 mg per 3/4 cup serving, and one stalk of broccoli contains 150 mg. If you have oatmeal for breakfast, a cup of macaroni and cheese for lunch, a couple of cheese wedges for a snack and broccoli for dinner, you've probably reached your calcium limit for the day.
Appropriate Intake
You may risk kidney stones if you consume either too much or too little calcium, according to the University of Arizona. Therefore, you should hit your target as precisely as you can, based on your age and gender, to avoid kidney stones. Men ages 19 to 70 years and women ages 19 to 50 years should get 1,000 mg of calcium per day, and women ages 51 years and older should get 1,200 mg per day. Men older than 70 years should also get 1,200 mg of calcium per day.
