Kidney stones are notoriously painful, so it’s important to know what causes them and do all you can to prevent them. Kidney stones are caused by a variety of factors, two of which are dehydration and a high-salt diet. And somewhat surprisingly, a diet low in calcium can also cause kidney stones—even though the stones themselves are mainly composed of calcium.
“One of the most common misconceptions is because most kidney stones are calcium, that dietary calcium supplements are a risk factor for kidney stones,” says Yale Medicine urologist Piruz Motamedinia, MD. “That’s actually contrary to the evidence.”
Instead, one of the biggest risk factors for higher concentrations of urine calcium is dietary sodium—not dietary calcium.
According to Dr. Motamedinia, many patients report that when they search the internet for advice on “kidney stone diets,” they read that it’s a good idea to steer completely clear of oxalates (an organic compound found in many plants). That can be difficult to do, says Dr. Motamedinia. Instead, he advises patients to increase their dietary calcium.
Dr. Motamedinia also explains that there are two main ways to prevent kidney stones: One is to dilute a patient’s urine with as much fluid as possible; and two is to remove what forms the kidney stones from the patient’s body.
In this video, Dr. Motamedinia discusses kidney stone prevention—and dispels some common myths about how they form.