[Different way of thinking in an adequate vitamin D intake for bone health between Japan and the West]

Japanese recommended dietary allowance of vitamin D is quite low and about half to one third of the West, however, 1alpha-OH-D as a drug is popular usage for osteoporosis patients in Japan. The different way of thinking of vitamin D may come from quite low calcium intake in Japanese and more biosynthesized vitamin D owing to a location lower in latitude of Japan. Still, recommended dietary allowance of vitamin D in the West will be raised much higher level in near future owing to many evidences demonstrating the shortages of vitamin D for optimal bone health in Western elderly. More researches will be needed to decide adequate intake of vitamin D for Japanese.