by Earl Staelin Well Being Journal
Vol. 15, No. 2, March/April 2006 (Reprinted here with permission from The Well Being Journal)
Americans have been taught that they need lots of calcium, especially post-menopausal women who frequently develop osteoporosis with the risk of spontaneous fractures. Older men also lose calcium in their bones, more gradually at first, although they tend to catch up with women when in their seventies. Adequate calcium absorption and levels of calcium in blood and tissues are of course essential for all children and adults for bones and teeth, and for women who are breast feeding or pregnant. In the U.S. 10 million men and women have osteoporosis, a disease of seriously weakened bones. One out of two women and one in eight men breaks a bone due to osteoporosis. After a hip fracture one in five dies within a year.
However, excess calcium intake may cause muscle spasms, the calcium may appear as unwanted deposits in organs and tissues, such as bone spurs or plaque in the wall of blood vessels or in kidneys, heart, and liver, and it may increase the risk of cancer and cause other symptoms, including migraine headaches, pain, kidney stones, depression, and heart arrhythmia. Americans consume milk and milk products as well as calcium supplements at one of the highest rates in the world. Yet we have one of the highest rates of osteoporosis in the world.
Of course the goal is to have calcium in the right amounts in all tissues. But how much do we need? Despite all that has been written about calcium, it is not at all clear how much calcium humans need. This article will show that the conventional wisdom about calcium, which a number of prominent nutrition authorities reject, is faulty and incomplete, and that optimal health requires a substantial revision of our thinking about calcium.
The conventional wisdom about calcium is embodied in the government guidelines for vitamins, minerals, and other nutrients. The current U.S. Recommended Dietary Allowance (RDA) for calcium is: for ages 9-18, 1,300 milligrams (mg)/day; ages 19-49, 1,000 mg/day; age 50 and over, 1,200 mg/day. In 1986 the RDA was raised from 800 mg/day for adults to present levels. The World Health Organization recommends 500 mg/day for children and 800 mg/day for adults. Professors such as Willard Willett, chairman of the Harvard Nutrition Department, T. Colin Campbell, professor emeritus of nutrition at Cornell University, and Marion Nestle, chairman of nutrition at NYU, believe that these current RDA’s are too high and are not supported by the evidence. On the other hand Prof. Robert Heaney of Creighton University, Bess Dawson-Hughes of Tufts University, past president of the National Osteoporosis Foundation, and a number of other prominent experts stand by the current RDA’s. The calcium proponents have the upper hand right now, with many doctors pushing calcium, and with calcium being added to orange juice and numerous other foods to make it easy for everyone to meet the RDA. The calcium proponents cite many studies in their favor, some of them involving fewer fractures, so it becomes necessary to sort out the apparent conflicts between studies.
Posted on The Well Being Journal (Link no longer available.)