These factors mainly concern the people at risk, especially those who have suffered from kidney stones in the past.

• Poor hydration. Drinking little decreases the volume of urine, so concentrates the salts in the urine and increases the risk of crystallization;
• Physical inactivity. Lack of physical activity causes a gradual loss of bone mass, hence the release of calcium;
• Taking certain medications Taking diuretics (including triamterene) or calcium-based antacids, for example, may increase your risk of developing kidney stones. Sulfonamides and some antivirals like indinavir also increase the risk of lithiasis. People at risk should check with their doctor or pharmacist about their medication;
• A very salty diet or very rich in sugars ;
• A diet with an excess of protein. Protein increases the levels of calcium, oxalate and uric acid in the urine, and lowers the level of citrate (a protective factor against stones)³. Studies suggest vegetarianism reduces risk of kidney stones^4,22,23. However, if the daily amount of protein is adequate, whether animal or vegetable, it does not affect the risk of kidney stones.⁵ ;
• A diet lacking calcium. Contrary to what one might think, calcium from food (dairy products, canned fish with bones, fruits, green vegetables, legumes, nuts) has a protective effect against kidney stones.^37,38.

  The suppléments of calcium, pris with meals, can have the same effect, but taken only, they may slightly increase the risk of kidney stones^9-11 .