Overconsumption of calcium can cause hypercalcemia. The upper limit (UL) for calcium intake is 2,500 mg daily from food and supplements.
People over the age of 50 should not take more than 2,000 mg a day, especially supplements, as this may increase the risk of certain diseases such as kidney stones, prostate cancer and constipation.
Some research has shown that in some people, calcium can build up in blood vessels with long-term high doses and cause heart problems.
Calcium is also a large metal that can block the absorption of other minerals necessary for the body such as iron and zinc.