Can I still take calcium tablets if I have kidney stones? "This is a confusion for many people. Some people believe that supplementing calcium can worsen stones, while others worry that not supplementing calcium can lead to osteoporosis. What is the relationship between calcium and stones? How should kidney stone patients supplement calcium? To answer these questions, the first step is to clarify the different causes of stones. Kidney stones include calcium oxalate stones, calcium phosphate stones, uric acid stones, magnesium ammonium phosphate stones, and cysteine stones. Calcium oxalate stones are the most common type, accounting for about 80% of all kidney stones. For patients with calcium oxalate stones, it is necessary to supplement calcium appropriately. The formation of calcium oxalate stones mainly depends on the concentration of oxalate in the blood. Calcium can combine with oxalate in the intestine to form unabsorbed calcium oxalate, which is excreted with feces. But if calcium intake is insufficient, oxalates in the intestine will be absorbed in large amounts, eventually excreted in the kidneys and combined with calcium, making it easier to form stones. Of course, some people may wonder why oxalate and calcium do not combine in the blood to form calcium oxalate stones? The reason is that the concentration of oxalate in the blood is extremely low, and although there is slightly more calcium, the product of the two concentrations is much lower than the solubility product (the concentration product can be understood as the "probability of ion encounter", and the solubility product is the "warning line" for dissolution. When the ion concentration product in the solution exceeds this line, the substance will crystallize, otherwise it will dissolve), just like two clumps of sand thrown into a swimming pool, they cannot touch each other at all. At the same time, there are many inhibitors in the blood, such as citrate, magnesium ions, albumin, etc., which flow quickly and cannot clump together; After reaching the kidneys, urine concentration increases the concentration of oxalate and calcium by dozens of times, while inhibition decreases, and the two "clump" into stones. Therefore, reasonable calcium supplementation not only does not aggravate stones, but can also prevent the formation of calcium oxalate stones. In fact, reasonable calcium supplementation is not only worth the attention of kidney stone patients, but also should be taken seriously by ordinary people. Chinese residents generally have insufficient calcium intake. According to the survey results of the "Report on the Nutrition and Chronic Disease Status of Chinese Residents (2020)", the daily calcium intake of adults aged 18 to 59 in China is 328.3 milligrams, which is less than half of the recommended amount (800 to 1000 milligrams). How to supplement calcium? The main food sources of calcium are milk and its products, tofu, leafy vegetables, cauliflower and bean pods, chili vegetables, shellfish and fish, citrus fruits, etc. Fresh milk and dairy products are excellent sources of dietary calcium, with a calcium content of 100 to 110 milligrams per 100 milliliters of fresh milk. In soy products, the calcium content of 100 grams of tofu is approximately 110 to 140 milligrams. Green leafy vegetables can also be a good source of dietary calcium, but when consuming green leafy vegetables for calcium supplementation, attention should be paid to reducing the intake of high oxalate vegetables such as spinach and amaranth. If the daily diet cannot meet the calcium intake requirements, calcium supplements can be considered. Common calcium tablets include inorganic calcium, organic acid calcium, chelated calcium, etc. Inorganic calcium generally has a high calcium content. Due to its low water solubility, it needs to be broken down by stomach acid to be absorbed. The calcium carbonate we often come into contact with is a type of inorganic calcium; Organic calcium salts have relatively good water solubility and are easier to absorb, but usually have lower calcium content, such as calcium gluconate, calcium lactate, and calcium citrate; There is also a type of chelated calcium that can increase the body's absorption, but the cost is relatively high. It is recommended to choose the appropriate dosage form under the guidance of a doctor. Besides calcium oxalate stones, about 10% of kidney stones are calcium phosphate stones, and calcium supplementation is not recommended for this group of patients; For patients with other types of kidney stones, calcium supplementation has no significant effect. It should be noted that calcium supplementation should be moderate, and long-term excessive calcium supplementation (greater than 2000 milligrams per day) can also increase the risk of kidney stones. (New Society)