Calcium supplementation in osteoporosis.

Although calcium is the most abundant inorganic constituent of the bone, indispensable for the maintenance of its physical strength, the role of calcium nutrition in the development of osteoporosis and the preventive and therapeutic significance of calcium supplementation in osteoporosis have been matters of intense controversy. The wide difference in the baseline nutritional intake of calcium among different groups and the variation in age of the patients studied may have been contributory factors. Emphasis has so far been placed on the rapid bone loss in the immediate postmenopausal period predominantly influenced by estrogen deficiency which has overshadowed the effect of calcium. The strong dependence of the effect of calcium preparation used tends to be forgotten. In the present study employing oyster shell electrolysate as the calcium source in patients with a mean age of approximately 80 years, bone mineral density was kept significantly higher than in age-matched, non-supplemented patients over a period of 2 years. In separate experimental studies, rats maintained on 2% calcium showed higher bone mineral content and lived longer than did controls maintained on 1% calcium. Age-associated deterioration of renal function and hyperlipidemia were also prevented by calcium supplementation.