By far the most important thing to do to prevent kidney stones is to drink plenty of filtered or bottled water - 2 litres a day - to flush the kidneys and urinary tract regularly. A lack of certain nutrients can also contribute, especially magnesium, vitamin B6, vitamin D and potassium, all of which are involved in calcium metabolism. So you should include green leafy vegetables, wholegrains, bananas, nuts and seeds in your diet on a regular basis. Vitamin A, abundant in carrots, red peppers, sweet potatoes and green leafy vegetables, also benefits the urinary tract and helps inhibit the formation of stones. Avoid antacids and minimize your consumption of animal protein, as it can cause the body to excrete calcium and uric acid, which can in turn contribute to the formation of the two most common forms of kidney stones.