Calcium Requirements and Recommended Dietary Allowances

Abstract

Calcium plays an essential role in the regulation of many metabolic processes, in neuromuscular events and in bone health. A number of proteins exist that specifically bind calcium, and calcium markedly influences the activities of many enzymes involved in cellular metabolism and differentiation. Recommended dietary allowances or intakes for calcium vary two-fold, in nearly all age categories in various countries throughout the world. The recommended dietray intake in Japan for most ages is somewhat lower than that in the United States. Median intakes of calcium in the United States decrease after 10 to 20 years of age. Whereas the median calcium intake of adult men approximates the RDA in the United States, that of adult women is considerably lower. The absorption and excretion of calcium are markedly affected, both by physiological and by dietary factors. Calcium intakes required to provide a balanced state in adults vary four-fold, depending on age, sex, diet and hormonal status. Dairy products are the best dietary source of bioavailable calcium. Inasmuch as the median calcium intake of elderly women in the United States is only 60 percent of the RDA, and the same group is highly susceptible to osteoporosis, the calcium intake in this group should probably be increased. © 1985, Center for Academic Publications Japan. All rights reserved.