EFFECT OF 1-ALPHA-HYDROXYVITAMIN D3 ON LOSS OF BONE-MINERAL DENSITY IMMEDIATELY AFTER ARTIFICIAL MENOPAUSE

To evaluate the effects of 1 alpha-hydroxyvitamin D-3 (1 alpha(OH)D-3) , a series of clinical trials, preventive and therapeutic, were perfor med in an open label manner in women immediately after oophorectomy. T he series included a total of 121 oophorectomized subjects, whose lumb ar bone mineral density (L2-4BMD) was followed by the use of dual ener gy X-ray absorptiometry. (1) Preventive trial: 61 women who had underg one premenopausal bilateral oophorectomy, were divided into 3 groups ( Group C: control; Group L: 0.25 mu g 1 alpha(OH)D-3/day; Group H: 0.50 -0.75 mu g 1 alpha(OH)D-3/day). The changes in BMD and chemical indice s were followed up for one year. (2) Therapeutic trial: the trial incl uded 60 premenopausally oophorectomized subjects having L2-4BMD lower than the normal control level minus 1SD which has been reported in age -matched normal Japanese women. These subjects were divided into 3 gro ups and treated in the same way as in the preventive trial. In the pre ventive trial, L2-4BMD decreased by 8.2%, 6.5% and 4.5% in groups C, L and H, respectively, at 12 months of treatment, whereas in the therap eutic trial, L2-4BMD decreased by 3.6%, 3.2% and 0.8% in the groups C, L and H, respectively, at 12 months of treatment. In conclusion, 1 al pha(OH)D-3 was found to be effective both to prevent the bone loss sub sequent to bilateral oophorectomy and improve low bone mass after ooph orectomy.