Kidney stones occur in up to 15% of the population. The incidence of stone disease is 0.1-0.4%, i.e. 100 to 400 out of 100,000 people form a
kidney stone every year. The recurrence rate is high, reaching 52% within 10 years and 75% within 20 years, respectively. Since urinary supersaturation, the driving force for crystallisation and stone formation, directly depends on nutritional habits, dietary recommendations are an important part of stone treatment. The benefit of urine dilution by means of a high fluid intake (urine volume at least 2.5 L/d) has been established by several studies. On the other hand, incorrect dietary recommendations, such as the restriction of
calcium as advocated for decades, can even promote stone formation! Indeed, large prospective trials have clearly demonstrated that the risk for stone formation decreases with increasing daily
calcium intake. It is therefore mandatory that low-
calcium diet is finally abandoned in patients with
calcium kidney stones and replaced by a sufficient
calcium consumption, i.e. 1200 mg per day. Furthermore, epidemiological studies confirm that a diet rich in
meat protein carries an increased risk for forming upper
urinary tract stones; thus, daily
protein intake should not exceed 1 g/kg
body weight, which corresponds with general recommendations for a healthy diet. Last but not least, more recent studies have shown that the consumption of high quantities of fruits and vegetables may protect against
kidney stone formation, since it raises urinary excretion of
citrate, an important inhibitor of crystallization. The present review emphasizes on the relations between nutrition and stone formation in the urinary tract and offers convenient and inexpensive measures for the prevention of recurrence of
nephrolithiasis.