[Bone and Nutrition. Vitamin D intake and bone].

Vitamin D insufficiency is one of the risk factors of osteoporosis. To know the vitamin D intake for the prevention of bone loss and fracture, it is necessary to evaluate the appropriate serum 25-hydroxyvitamin D (25-D) concentration for bone health, and the vitamin D intake to maintain its concentration. Although vitamin D intake 15 and 20 μg/d have been set as RDA (Recommended Dietary Allowance) in USA/Canada DRIs (Dietary reference intakes), 5.5 μg/d has been set as AI (adequate intake) in Japanese DRIs (2015). While reference values in Japan and USA/Canada were quite different, both DRIs are common in that it aim to maintain the serum 25-D concentration to more than 50 nmol/L. In the present review, vitamin D intakes and bone health, vitamin D status in Japanese people, DRIs for vitamin D and improvement of vitamin D insufficiency are reviewed.