If you are taking calcium supplement, be aware that calcium is available in different forms e.g Calcium Lactate, Calcium Bicarbonate, etc. A recent study showed that taking too much of Calcium Carbonate (commonly derived from shells, seabed and limestones) may cause deposition of calcium in the blood vessels, resulting in hardening of arteries which can trigger a heart attack. The dosage of calcium supplement also matters, calcium absorption is most efficient with less than 500mg of elemental calcium per intake. Opt for Calcium Lactate that is highly soluble, easily digested and absorbed by the body, thus less risk of calcium deposition in the body.