[Treatment of osteoporosis by active vitamin D]

Supplementation of active vitamin D has been thought to be reasonable for those who convert insufficiently vitamin D to active form, especially for senile persons. Treatment of osteoporosis by vitamin D are accepted as not only supplementation of vitamin D but also direct activation of bone turnover. Several previous clinical trials suggest active vitamin D prevents fractures more effectively rather than the increase of the bone mass. The calcium intake of Japanese people is less than that of Western countries, and many of Japanese have the vitamin D receptor genotype which is more responsive to vitamin D. Therefore, it is probable that active vitamin D is more effective for Japanese than Western people.