These include unrefined calcium carbonate from oyster shells or limestone, bone meal, and Dolomite. How to Take It You should take small doses throughout the day, and drink 6 to 8 cups of water throughout the day to avoid constipation. Adults ages 19 to 50 need 1,000 mg of calcium each day. After age 50, adults need 1,200 mg each day. Adolescents ages 9 to 18 need 1,300 mg each day.
High doses can cause kidney stones and other serious problems.
Talk with your provider about your calcium needs if you have any thyroid or kidney problems, or if you have hormone or vitamin deficiencies. Possible Interactions Calcium can interfere with the absorption of tetracycline. Some corticosteroid medications such as glucocorticoids also inhibit the absorption of calcium, thereby increasing the risk for osteoporosis over time. Two different classes of diuretics interact with calcium in opposite ways thiazide diuretics such as hydrochlorothiazide can raise calcium levels in the blood, while loop diuretics such as furosemide and bumetanide can decrease calcium levels. People who are taking digoxin should have calcium blood levels monitored closely.