Prevention of calcium-containing urinary tract stones (especially to prevent recurrence)

　　0) Increase fluid intake: see previous blog post on how to drink water to prevent relapse in patients with kidney stones

　　1) Dietary calcium content:

　　 Normal range (800 mg/day) or an appropriate high-calcium diet is of clinical value in preventing the recurrence of urinary tract calcium-containing stones. However, dietary calcium supplementation (ie, various calcium tablets) may be detrimental to stone prevention, because an uncontrolled high-calcium diet will increase urine supersaturation levels. It is recommended to eat more dairy products (milk, cheese, yogurt, etc.), tofu and small fish. Adult daily calcium intake should be 800-1000 mg. It is recommended that patients with absorptive hypercalciuria take a low-calcium diet, and it is not recommended that other patients take a calcium-limited diet.

　　Preventing recurrence of calcium-containing stones through drug calcium supplementation is only suitable for intestinal hyperoxaluria. Oral administration of 200-400mg calcium citrate can increase urine output while inhibiting urine oxalate excretion Excretion of citric acid.

　　 2) Limit the intake of oxalic acid in the diet:

　　Although only 10% to 15% of urine oxalic acid comes from the diet, but a large amount of foods rich in oxalic acid Later, the excretion of oxalic acid in the urine will increase significantly. Patients with calcium oxalate stones, especially those with hyperoxaluria, should avoid ingesting foods rich in oxalic acid such as cabbage, almonds, peanuts, beets, parsley, spinach, rhubarb, black tea and cocoa powder. Among them, the content of oxalic acid in spinach is the highest, patients with calcium oxalate stones should pay attention to avoid spinach.

　　Low calcium diet will promote the absorption of oxalate in the intestine and increase the excretion of oxalate in urine.

　　Calcium supplementation is beneficial for reducing intestinal oxalate absorption, however, it is only suitable for patients with intestinal hyperoxaluria.

　　3) Limit sodium salt intake:

　　High sodium diet will increase urinary calcium excretion, daily sodium intake should be less than 2 grams.

　　 4) Limit excessive protein intake:

　　Diet low carbohydrate and high animal protein diet is related to the formation of calcium stones. A high-protein diet causes increased excretion of urinary calcium and urinary oxalate, while reducing urinary citrate excretion and lowering the pH of urine. It is one of the important risk factors that induce the formation of calcium stones in the urinary tract.

　　It is recommended to eat a nutritionally balanced diet, and it is very important to maintain a balanced nutrition of the three meals in the morning, middle and evening. Avoid excessive intake of animal protein, the daily intake of animal protein should be limited to 150g. Among them, the daily protein intake of patients with recurrent stones should not exceed 80g. ,

　　5) Weight loss:

　　Research shows that overweight is one of the most important factors for the formation of urinary tract stones.

　　6) Increase the intake of fruits and vegetables:

　　Intake of fruits and vegetables in the diet can dilute the risk factors of calculi in the urine, but it does not affect the urinary potassium and Urine citrate concentration. Therefore, increasing the intake of fruits and vegetables can prevent the recurrence of stones in patients with low citric aciduria.

　　7) Increase coarse grains and cellulose diet: Rice bran can reduce the excretion of urinary calcium and reduce the recurrence rate of urinary tract stones, but to avoid cellulose foods rich in oxalic acid such as wheat bran.

　　 8) Reduce the intake of vitamin C: Vitamin C can generate oxalic acid after natural conversion. After taking vitamin C, urine oxalate excretion will increase significantly, and the risk of forming calcium oxalate crystals will increase accordingly. Although there is no data to indicate that the intake of large doses of vitamin C is related to the recurrence of calcium oxalate stones, it is recommended that patients with recurrent calcium oxalate stones avoid large doses of vitamin C. Recommend that their daily intake of vitamin C should not exceed 1.0 grams.

　　9) Limit high-purine diet: Patients with calcium oxalate stones with hyperuricuria should avoid a high-purine diet. It is recommended that the daily intake of purine in food is less than 500 mg. Foods rich in purines are: animal offal (liver and kidney), poultry skin, skinned herring, sardines, anchovies, etc.