Background: Vitamin D insufficiency is common in northern countries during wintertime. In Finland, after the recommendation by the Ministry of Social Affairs and Health, vitamin D has been added to liquid milk products and margarines from February 2003.
Objective: We determined the effects of national policy on vitamin D fortification on vitamin D status among young Finnish men.
Design: A comparison before and after intervention with study population of 196 young Finnish men (18-28 years) was carried out. Serum 25-hydroxyvitamin D3 (25-OHD3) concentrations were determined with the OCTEIA enzymeimmunoassay by IDS (Immunodiagnostic Systems Limited, Bolden, UK) in January 2003 (n = 96) and in January 2004 (n = 100), nearly 1 year after national vitamin D fortification had started.
Results: The mean serum 25-OHD3 concentrations during the wintertime increased by 50% after implementation of the vitamin D fortification of dairy products. Correspondingly, the prevalence of vitamin D insufficiency (serum 25-OHD3 < 40 nmol/l) was decreased by 50% from 78% in January 2003 to 35% in January 2004.
Conclusions: Our results demonstrate that national vitamin D fortification substantially improved the vitamin D status of young Finnish men. Still, a third remained vitamin D insufficient.