Compared to calcium citrate, calcium carbonate is cheaper and contains more elemental calcium per serving. It does however cause more constipation. Calcium citrate absorbs better in individuals with inflammatory bowel disease and malabsorption problems, according to Mayo Clinic.
The National Institute of Health recommends that men and women between the ages of 19 and 50 consume 1,000 milligrams of calcium per day. This amount increases to 1,200 milligrams per day for women after the age of 51 and for men after the age of 71.
Elemental calcium is the main ingredient in calcium supplements and is absorbed by the gastrointestinal system to help with bone formation and other important functions. Calcium carbonate is one of the four commonly used calcium supplements. It contains 40 percent elemental calcium, compared to 21 percent in calcium citrate. Calcium lactate contains 13 percent elemental calcium, followed by calcium gluconate with 9 percent, according to Mayo Clinic.
The side effects of taking calcium supplements usually involve gastrointestinal symptoms such as bloating and constipation. Excessive intake of calcium can increase the risk of kidney stone formation and the development of prostate cancer. It can also impair the absorption of other important dietary minerals. Individuals taking certain medications, such as blood pressure agents, and drugs that affect bone mineralization and metabolism, should seek advice from their health care professional before taking calcium supplements, according to Mayo Clinic.