Vitamin D requirement and setting recommendation levels - current Nordic view.

At the latitude of the Nordic countries, where there is almost no dermal formation of vitamin D during winter, dietary intake is required to avoid deficiency. Dietary intake is of the order of 4-5 microg/day but varies widely. The lowest intake is seen among adolescents. Low levels of serum 25(OH)D have been found in population groups in all Nordic countries. The drop in 25(OH)D during the winter months may be considerable, falling below acceptable levels (50 nmol/L) in one half of the population. To ensure an acceptable vitamin D status is maintained in the population and to diminish the seasonal drop in 25(OH)D, the Nordic Nutrition Recommendations 2004 increased the vitamin D recommendation for the age group 2-60 years by 50% from 5 microg/day to 7.5 microg/day. To attain such an intake at the population level, public health actions, including information dissemination and increased fortification of foods, are necessary.