Significant progress was made during the first three years of the OPTIFORD project:

• All intervention and observational studies were finished by the end of 2003. In general drop-out was low and compliance high.

• Work Package 1. The intervention study with Danish and Finish young girls was completed. Results from baseline data are calculated. All samples from baseline visits has been analysed and data compiled. Samples from second and third visit has been analysed, and data has been processed.

• Work Package 2. The intervention study in elderly Finish persons was finished, all chemical analysis performed, and data processed. Peer reviewed scientific papers are published.

• Work Package 3. The intervention in Muslim immigrants was finished in 2003. Baseline samples are analysed and results calculated. Blood and urine samples from second and third visit are analysed and data processed.

• Work Package 4. The observational study in all 5 countries is finished.

• Solar exposure was measured and correlated to vitamin D status.

• A dataset containing vitamin D in foods from all countries was compiled, and vitamin D intake in all participants calculated. The correlation between vitamin D intake and vitamin D status was investigated.

• Work Package 5. Fortified bread of different types (wheat and rye bread) were developed and analysed to verify content, dispersion and stability of vitamin D in the bread.

• Bio-availability of vitamin D from fortified bread was tested in subjects with low vitamin D status.

The work has resulted in the following scientific papers:

Towards a strategy for optimal vitamin D fortification (OPTIFORD)
R. Andersen, C. Brot, L. Ovesen
Nutrition Metabolism and Cardiovascular Diseases, 2001, 11, 74-77

Geographical differences in vitamin D status, with particular reference to European studies
L. Ovesen, R. Andersen, J. Jakobsen
Proceedings of the Nutrition Society, 2003, 62, 813-821

Teenage girls and elderly women living in nothern Europe have low winter vitamin D status
R. Andersen, C. Mølgaard, L.T. Skovgaard, C. Brot, K.D. Cashman, E. Chabros, J. Charzewska, A. Flynn, J. Jakobsen, M. Kärkkäinen, M. Kiely, C. Lamberg-Allardt, O. Moreiras, A.M. Natri, M. O'Brien, M. Rogalska-Niedzwieds, L. Ovesen
European Journal of Clinical Nutrition, 2005, 59, 533-541

A seasonal variation of calcitropic hormones, bone turnover and bone minderal density in early and mid-puberty girls - a cross-sectional study
H.T. Viljakainen, A. Palssa, M. Kärkkäinen, J. Jakobsen, K.D. Cashman, C. Mølgaard, C. Lamberg-Allardt
British Journal of Nutrition, 2006, 95, 1-7

A positive dose-response effect of vitamin D supplementation on site-specific bone mineral augmentation in adolescent girls: a double-blinded randomized placebo-controlled 1-y intervention
H.T. Viljakainen, A-M. Natri, M. Kärkkäinen, M.M. Huttunen, A. Palssa, J. Jakobsen, K.D. Cashman, C. Mølgaard, C. Lamberg-Allardt
Jounal of bone and Mineral Research, 2006, 21, 836-844

Bread fortified with cholecalciferol increase the serum 25-hydroxyvitamin D concentration in women as effectively as a cholecalciferol supplements
A-M. Natri, P. Salo, T. Vikstedt, A. Palssa, M. Huttunen, M.U.M. Kärkkäinen, H. Salovaara, V. Piironen, J. Jakobsen, C. Lamberg-Allardt
The Journal of Nutrition, 2006, 136, 123-127

Pakistani immigrant children and adults in Denmark have severely low vitamin D status
R. Andersen, C. Mølgaard, L.T. Skovgaard, C. Brot, K.D. Cashman, J. Jakobsen, C. Lamberg-Allardt, and L. Ovesen
European Journal of Clinical Nutrition, 2007, in press