Calcium needs of the elderly to reduce fracture risk.
Contemporary calcium intakes in the industrialized nations are substantially lower than those to which human physiology is adapted by evolution. As a result, compensatory adjustment is required lifelong. This adjustment consists of high levels of parathyroid activity, leading to parathyroid hyperplasia, high circulating levels of 1,25(OH)2D and high bone turnover. The capacity of these compensatory mechanisms to provide sufficient calcium to offset daily losses from the body declines with age; hence, increasingly the body tears down bone to access its calcium. As a result, the calcium requirement for skeletal maintenance is said to rise with age. Supplemented intakes to a total in the range of 32.5-42.5 mmol (1300-1700 mg)/day have been shown to arrest age-related bone loss and to reduce fracture risk in individuals 65 and older and intakes of 60 mmol (2400 mg), to restore the setting of the parathyroid glands to young adult values. Intakes at such levels also minimize the expression of other disorders such as colon cancer, hypertension and obesity, all of which, while multifactorial, have a calcium deficiency component. Milk, mainly because of constructive interactions among its several key nutrients, is probably the most nutritionally and cost effective way of meeting the calcium requirement in the elderly.
Heaney
R P
RP
Creighton University, Osteoporosis Research Center, Omaha, Nebraska 68131, USA. rheaney@creighton.edu
D000368:Aged; D000375:Aging / Q000502:physiology*; D001862:Bone Resorption; D002136:Calcium, Dietary / Q000008:administration & dosage* / Q000378:metabolism*; D005260:Female; D050723:Fractures, Bone / Q000209:etiology* / Q000517:prevention & control; D006801:Humans; D008297:Male; D009751:Nutritional Requirements; D010280:Parathyroid Glands / Q000502:physiology*; D012307:Risk Factors
D002136:Calcium, Dietary