Does Calcium Consumption Cause Kidney Stones and Constipation?

First, the important fact is that 90% of the composition in kidney stone is calcium oxalate. Oxalate is a type of organic compound found in certain foods (such as spinach and beets), and can have chemical reactions with calcium to form the insoluble calcium oxalate. So to a certain degree, kidney stones are the result of abnormal metabolism of calcium, not because of its high intake. A broad studies have shown that sufficient daily intake of calcium may significantly reduce the risk of kidney stones. The calcium sold on market contains pretty much 100% calcium carbonate which is not a natural form of calcium, it alone is very difficult to be absorbed by human body. Without assistance of the vitamin D, taking this form of calcium basically is useless. Calcium left out without being absorbed during metabolic process is what may cause constipation and formation of stones. Although calcium utilization and absorption are equal in calcium carbonate and calcium citrate with the presence of vitamin D, calcium carbonate may cause constipation in some individuals. So put it bluntly, kidney stones and constipation are caused by taking "bad" calcium, not because of high calcium consumption!

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