[Rickets/Osteomalacia. Vitamin D action:Lessons from animal models.].

Animal studies using mice model such as vitamin D deficiency and global and conditional VDR knock out(KO)mice have disclosed that the physiological role of vitamin D strongly depends on the calcium balance. Vitamin D stimulates active intestinal calcium transport mechanism, thereby maintains normocalcemia that has priority over skeletal integrity. Besides the biological significance of vitamin D extensively studied, its precise function in non-classical target needs further investigation.