| [ Summary ] |
With increased aging of the population, osteoporosis has become an important health issue. Although the development of diagnostic procedures and medications for osteoporosis and osteoporotic fractures are widely needed, much attention has been focused on primary prevention based on nutritional approaches. In addition to calcium, vitamin D is a nutrient closely related to osteoporosis. Its metabolite, 25-hydroxyvitamin D, has been used as a nutritional measure for setting requirements for vitamin D intake and for screening vitamin D-lacking subjects in the general population. So far, serum PTH concentrations, intestinal calcium absorption potency, bone turnover markers, and bone mineral density have been used as clinical measures for setting the reference value of serum 25-hydroxyvitamin D concentrations. Internationally, there have been a number of reports proposing approximately 50 - 80 nmol/l as a reference value for healthy elderly subjects, however, epidemiological data used for setting the reference values are limited at present. |