[Vitamin D and calcium for the treatment of osteoporosis]

Vitamin D and calcium are indispensable for the maintenance of bone mass and integrity. Active vitamin D3 has been most widely used in Japan for the treatment of osteoporosis. These drugs mildly increase bone mineral density, but it has little consistent effects on bone metabolic markers. Although weak, there is also some clinical evidence for their efficacy as a fracture-preventing drug. Recent reports suggest that vitamin D3 not only enhances intestinal calcium absorption but may also improve neuromuscular function to reduce the number of falls, thereby contributing to fracture prevention. Besides such extraskeletal effects, vitamin D analogues may also have direct bone anabolic effects, preventing fractures even under native vitamin D and calcium supplement.