There is a saying on the Internet that calcium supplementation can cause kidney stones. But is it really the case?
Answering experts
Zhou Fude, Chief Physician, Department of Nephrology, Peking University First Hospital
When the concentration of oxalic acid, calcium, uric acid and other soluble substances in the urine is too high, crystals can be formed. The abnormal accumulation of crystalline substances in the kidney will lead to kidney stones. The main causes of kidney stones are abnormal organic metabolism, urinary tract obstruction, infection, foreign bodies, etc. Proper calcium supplementation in time will not cause kidney stones.
Among kidney stones, calcium oxalate stone is the most common one, which is caused by the high concentration of oxalate in the human body. Calcium and oxalic acid are mainly taken from food. The more oxalate the body absorbs, the higher the risk of kidney stones.
When people eat high calcium food in a timely and appropriate amount, calcium and oxalic acid will combine in the intestinal tract, producing insoluble calcium oxalate precipitation, avoiding oxalic acid from being absorbed by the blood, so that it can be excreted with feces. Therefore, reasonable intake of calcium can not only reduce oxalate absorption, but also prevent the formation of calcium oxalate kidney stones.
