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Special Issue "Calcium Needs of Older Adults"
A special issue of Nutrients (ISSN 2072-6643).
Deadline for manuscript submissions: closed (31 December 2012).
Department of Nutrition, Schools of Public Health and Medicine, University of North Carolina, 2218 Mcgavran-Greenberg Hl, 135 Dauer Drive, Campus Box 7461, Chapel Hill 27599-7461, USA
Fax: +1 919 966 7216
Interests: nutrition and bone; nutrition and the metabolic syndrome; nutrition and renal function
Twenty % or more of US citizens have calcium intakes that exceed the Recommended Dietary Allowances (IOM, 2011). Spinal and hip NHANES data on bone mineral density (BMD) of older male and female adults of different ethnicities in the USA do not show differences in BMD of the spine and hip across quintiles of calcium intakes in this 2005-2006 analysis. Assuming calcium retention occurs at higher levels of intake, the question becomes: Where does the extra calcium go in the bodies of subjects in the highest quintiles? Certainly, some small amounts of calcium enter bone as part of the normal turnover of the mineral phase. Some is excreted in urine, more typically in those with higher quintiles of calcium intake than those in the lower quintiles. Recently, several researchers have suggested that a substantial portion of the retained calcium following dietary intake is deposited as new ectopic bone in arterial walls throughout the body, but especially in specific organs, most notably coronary arteries, heart valves, and the aorta. Measurement of coronary artery calcification measured by electron beam or spiral-computerized tomography provides a research tool to investigate the relationship between differing levels of calcium intake and total atherosclerotic burden. The adverse effects of ectopic vascular calcification include events related to ischemia (atherosclerosis) and arterial stiffening (arteriosclerosis). Both of these processes are associated with higher rates of morbidity and mortality in normal subjects and in patients with diabetes and chronic kidney diseases. To date, two reports have been published that suggest increased cardiovascular disease morbidity and mortality among high-calcium consumers, especially older women. Older adults may also develop brain lesions from excessive calcium intake. Ongoing efforts are aimed at understanding the initiating events in ectopic vascular calcification and relationships with established atherosclerosis in major arteries of the body. Another major question is whether optimal intake range of calcium, at or even slightly below the RDA, may lower the risk of arterial calcification and organ dysfunction.
Prof. Dr. John J.B. Anderson
Dr. Martha E. Payne
- dietary and supplemental calcium
- arterial calcification
- heart disease
- optimal calcium intake
- mechanisms of bone formation