Taking calcium can cause mild side effects including belching, gas, cramps and bloating. Calcium is usually safe when taken in proper amounts, according to WebMD. However, calcium in excess of 1300 milligrams can cause more intense side effects, with some research linking high calcium intake with an increased risk of heart attacks and prostate cancer, explains Mayo Clinic. Additionally, calcium supplements should not be combined with certain medications including ceftriaxone, or Rocephin, and certain antibiotics, notes WebMD.
Calcium supplements can interact with many different prescription medications. These include blood pressure medications, synthetic thyroid hormones, bisphosphonates, antibiotics and calcium channel blockers. Depending on what medications a person is taking, it is necessary to take the supplement with meals or between meals, states Mayo Clinic.
Calcium is used for treatment and prevention of low calcium levels and resulting bone conditions including osteoporosis, rickets and osteomalacia. Calcium can be used for premenstrual syndrome, or PMS; leg cramps in pregnancy; high blood pressure in pregnancy, or preeclampsia; and reducing the risk of colon and rectal cancers. Some people use calcium for complications after intestinal bypass surgery, high blood pressure, high cholesterol, Lyme disease, to reduce high fluoride levels in children and to reduce high lead levels. Calcium carbonate is used as an antacid for heartburn. Calcium carbonate and calcium acetate are also used for reducing phosphate levels in people with kidney disease, states WebMD.