I checked a few websites and they all stated that 2,500 mg of calcium per day was an overdose with some possible consequences such as kidney stones, nausea and vomiting, constipation or diarrhea (I guess you take your pick), and coma. Remember that you get calcium through food as well, things such as milk, ice cream, cheese, broccoli, kale, bok choy, almonds, etc. Please be careful to not overdo the calcium.