For years, the medical community has told patients prone to kidney stones to reduce calcium in the diet. That was terrible advice, according to a major study published in the New England Journal of Medicine.

Low-calcium diets may actually increase kidney stones in some patients while also putting them at risk for osteoporosis.

Low Calcium Diet Produced 40 Percent More Stones

The Italian study, conducted by the University of Parma, divided 120 men into two groups — half ate a low-calcium diet, the other half ate a diet with normal calcium and but low in protein and salt. After five years, men on the low-calcium diet had more than 40 percent more kidney stones.

The Culprits? Oxalate, Salt and Meat

Study authors said that people on a low-calcium diet excrete less calcium in their urine but more of another substance — oxalate — that combines with calcium to form most kidney stones. Also, dietary salt and the proteins in meat produce excess calcium in the urine.

Roles of Your Gender, Genetic Make-Up and History

Eighty percent of sufferers are men, and 13 percent of the total population will get a kidney stone in their lifetime. Once you have a stone, there is a 50-50 chance of getting another one within five years.

Eat Better Sources of Calcium

How can you prevent kidney stones in your family? Most important is a diet with adequate calcium, but lowered salt and meat protein, such as the calcium you get from yogurt. Also, if you eat meals regularly throughout the day and drink plenty of water, your body will be better able to clear itself of excess calcium.

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