Many studies have shown that calcium is an essential nutrient for bone health. Every day, approximately 10,000 milligrams of calcium move in and out of the skeleton. Much of this movement is part of the active process of bone remodeling, which keeps the skeleton healthy and renews parts that need to be repaired.
Vitamin D is also involved in bone remodeling. It aids the absorption of calcium from the intestine into the bloodstream, and helps calcium in the blood move into bone tissue that is newly formed by cells called osteoblasts.
The skeleton must have enough calcium to meet the demands of bone remodeling. The amount of calcium that individuals need varies, but adults typically require about 1,200 to 1,500 milligrams daily. Generally, a personís diet does not provide enough calcium because people do not consume very large amounts of dairy foods, which are the best sources. Therefore, calcium and vitamin D supplements are necessary for many individuals to meet their daily requirements.
Our recommendations for total intake (food source plus supplements) is in agreement with the recent guideline released by the Institute of Medicine and reported in the New York Times on November 29, 2010.
Calcium and vitamin D recommendations as posted in the New York Times on 11/29/10.
A recent review article published in the British Medical Journal looked at the results of several studies of calcium supplements and found that calcium supplements taken alone may increase the risk of non-fatal heart attack, or myocardial infarction. However, this review publication was not based on a prospective, randomized clinical trial, which is the gold standard of medical research. Two recently published prospective, randomized clinical trials do not show an increase of heart attacks with calcium supplementation.
The Food and Drug Administration and the American Society for Bone and Mineral Research are continuing to research this important issue. In the meantime, people should be aware that:
A recent report by the Practice Committee of the American Society for Bone and Mineral Research reviewed all available data; their conclusions were also summarized on their blog. Dr. Bockman considers this report to be the definitive word on calcium supplements and cardiovascular events.
People who have concerns about taking calcium supplements should discuss this issue with their doctors.
Reviewed and Updated: 6/13/2011
Summary by Allyson Collins, MS