Vitamin D-mangel. Definition og praevalens i Danmark
Sammanfattning
During the last two decades, biochemical assays for 25-hydroxyvitamin D have been available, and based on plasma measurements various definitions of vitamin D deficiency have been suggested. Whereas severe vitamin D deficiency is usually recognised relatively easy, it has been more difficult to delimit the more subtle forms of vitamin D insufficiency. Today, a suboptimal vitamin D status is considered to be when the plasma 25-hydroxyvitamin D level is below 50 nmol/L. Vitamin D insufficiency is defined as a plasma concentration between 25 and 50 nmol/L, whereas the term deficiency is used if the concentration is below 25 nmol/L. An increased bone turnover as well as an increased risk of osteoporotic fractures has been found in subjects with vitamin D insufficiency. In blood donors and in free-living elderly Danes, vitamin D deficiency has been found in 18% and 31%, and vitamin D insufficiency in 42% and 47%, respectively. Thus, a suboptimal vitamin D status is common among Danes. It is therefore important to consider how their vitamin D status can be improved.