Among calcium-containing stones calcium oxalate stones are the most common stones, accounting for 70-80% of urinary stones and can be calcium oxalate alone or in combination with other calcium salts. Its dietary restrictions include protein, sodium, refined sugar, fat and fiber modifications. A foreign scholar analyzed 10,617 urinary stones by infrared spectroscopy and found that 86% of stones had calcium oxalate and 80% had calcium phosphate, and there was a linear relationship between calcium intake and urinary calcium, so it is believed that increased calcium intake increases the risk of kidney stone formation. However, it has been shown that the commonly recommended practice of restricting calcium in the diet does not reduce but rather increases the incidence of kidney stones. A low-calcium diet promotes the absorption of intestinal oxalates and causes hyperoxaluria, which in turn promotes the formation of urinary stones. Giving patients with urinary stones a low-calcium diet may be more harmful than a normal calcium diet. Restriction of calcium intake stimulates the secretion of vitamin D3, promotes bone resorption, increases urinary calcium excretion, and increases the risk of urinary stone formation. High urinary calcium is classified into 3 types: Type I is non-diet-dependent; Type II is diet-dependent; and Type III is secondary to renal phosphorus leakage. Dietary calcium restriction reduces urinary calcium only in type I and type II absorptive hypercalcemia, and only type II can reach the normal range. Therefore, a low-calcium diet can only reduce urinary calcium in type II absorptive hypercalcemia, and must be accompanied by a low-oxalate diet to avoid secondary hyperoxaluria. Restricted dietary calcium should not be used for other types of hypercalcemia. The recommended daily calcium intake for patients with type II hypercalcemia is 400-600 mg, do not go below 400 mg or you will create a negative calcium balance. Do not exceed 1 gram either, as this may promote stone formation. The role of calcium supplementation in postmenopausal women is controversial. Calcium supplementation in premenopausal women increases urinary calcium only during the first few days and then decreases the absorption of calcium in the intestine due to inhibition of parathyroid hormone and 1,25 dihydroxyvitamin D3 synthesis, thus reducing the effect of oral calcium. In postmenopausal women, the effects of oral calcium supplementation are hampered by osteoporosis and disorders of vitamin D and parathyroid hormone metabolism, as well as the decreased intestinal calcium absorption capacity in the elderly. For these reasons, calcium supplementation in postmenopausal women increases the risk of stone formation only during the first few months of calcium supplementation, and it is prudent to increase water intake during this period. Postmenopausal women with type II absorptive hypercalcemia should be treated with a low-calcium, low-oxalate diet, as with other type II patients. Regardless of the type of stone, it is essential to increase the amount of water consumed to aid in the elimination of the stone and to dilute the urine to increase the volume of urine. Drink about 3,000 to 4,000 ml of water per day to maintain a daily urine output of 2,000 ml or more.