Do Calcium Pills Cause Kidney Stones?

Q. I take a medication (Zonegran) for epilepsy that makes me prone to kidney stones. I've passed one (ouch!) and have another, though it's not positioned to pass immediately. You often suggest taking 600 milligrams of calcium daily, but won't that make me form more kidney stones?
-- Paul, via e-mail

A. Since the most common type of kidney stones (calcium oxalate pebbles) form when calcium and oxalic acid hook up in urine (yep, pee is their idea of a singles bar), your question makes perfect sense. So our answer may sound a little crazy: Calcium pills, taken with meals, can actually protect you from painful kidney stones. Why? Calcium binds with oxalate in food, which prevents it from getting into your urinary tract.

There are other steps you can take to help prevent kidney stones. The most important is drinking lots of water. The rule of thumb if you've had a kidney stone is at least 3 quarts a day (other fluids count, too). Start by washing down your Zonegran with a big glassful. Then just keep at it. (Find out why vitamin D may also keep you out of kidney stone trouble.)

It's smart to measure your water intake for a few days (3 quarts equals 12 measuring cups) until you instinctively know how much you need. Every time you eat anything, drink a glass of water. Have a glass before you go to bed. If you get up to pee during the night, have another glass. Drink moderate amounts of orange juice, lemonade, coffee, tea, wine and beer, too. Research shows all can deter stones. Still, water is your kidneys' BFF.

Salt, however, is not. Sodium increases calcium in urine, which ups your chance of kidney stones. Skip the highly processed "salt bombs" your body doesn't need anyway (e.g., fast food, canned soups/vegetables, deli meats, pre-made frozen dishes, pizza, hot dogs, sausage). Limit these sneaky sources of salt, too. Grapefruit juice, cola, and cranberry juice may also cause trouble. Definitely avoid spinach, rhubarb, nuts, and wheat bran. These normally healthy foods increase oxalate in urine, which is exactly what Zonegran takers and other kidney-stone makers don't need.

Follow this healthy plan and you could cut your risk of kidney stones by 45%!