Calcium may decrease risk of colon cancer.




J Natl Cancer Inst

Related Monographs

Consumer Data: Calcium
Professional Data: Calcium


Calcium is the most abundant mineral in the human body. Average healthy males have about two and a half to three pounds of calcium while females have about two pounds. Approximately 99 percent of calcium is present in the bones and teeth, which leaves only about one percent in cells and body fluids. While the most important function of calcium involves the maintenance of skeletal health, the small percentage of calcium outside the bones is used to maintain a variety of vital body functions.

As most people know, calcium is crucial for the development and long-term health of bones and teeth. The body's need for calcium is greatest during periods of rapid growth including childhood, pregnancy, and lactation. Calcium is also necessary for a wide array of other functions. Calcium may initiate muscle contractions. For this reason it plays a vital role in maintaining a healthy heartbeat. It is also involved in the body's blood clotting process. On the cellular level, calcium regulates the passage of nutrients and wastes through cell membranes. It is also involved in the regulation of various enzymes that control muscle contraction, fat digestion and metabolism. Finally, calcium regulates the transmission of nerve impulses.

A recent study looked at the potential role for calcium in colon cancer risk. Using two prospective cohort studies, investigators examined the association between calcium intake and colon cancer risk. Over 87,000 women and 47,000 men completed food questionnaires and provided information on their lifestyles and medical history. During course of the study, 626 women and 399 men were diagnosed with colon cancer. Combining these cases, researchers found an inverse link between high calcium intake and distal colon cancer. No association was found in calcium and proximal colon cancer. Researchers found that additional calcium intake above 700 mg daily did not seem to further decrease the cancer risk. Although further investigations are warranted, the authors stated that a moderate 700 mg of calcium daily was associated with a reduced colon cancer risk.1


1. Kana Wu. Calcium Intake and Risk of Colon Cancer in Women and Men. J Natl Cancer Inst. Mar 2002;94:437-446.