AGING AND CALCIUM-METABOLISM

Ageing alters the metabolism of calcium and vitamin D in a number of w ays. Intake of calcium and vitamin D, exposure to sunlight, cutaneous production of vitamin D-3, renal production of 1,25-dihydroxyvitamin D (1,25(OH)(2)D-3), intestinal absorption of calcium and the ability to adapt to a low calcium diet may all be reduced in elderly subjects. A s a consequence, secondary hyperparathyroidism often occurs with agein g and can contribute to accelerated bone loss. In fact, alterations in calcium and vitamin D metabolism may be widespread in the ageing popu lation and play a central role in the pathogenesis of senile (age-rela ted) osteoporosis. From a preventive point of view, recent interventio n studies have indicated the need to optimize calcium intake and to ma intain serum 25(OH)D-3 levels within the normal range in elderly peopl e.