Vitamin D related osteomalacia consisted of vitamin D deficient and resistant forms. Vitamin D deficiency was frequently suggested as a complication of osteoporosis. Vitamin D was synthesized in the skin from pro vitamin D by sunlight. And the elderly residents in the nursing home who do not want to come outside frequently are at high risk. Also, the people taking anti-convulsant are the case, because the medications promoted the catabolism of vitamin D through the induction of an enzyme linked to cytochrome P450. Since the effect of bisphosphonate was reported to be decreased in vitamin D deficiency, we have to keep in mind for adding native or active vitamin D for the target people of osteoporosis.