Consequences of Removing Iron Fortification of Flour on Iron Status among Danish Adults: Some Longitudinal Observations between 1987 and 1994

Background. Health authorities recommend that populations consume a diet providing sufficient iron, and in order to prevent iron deficiency, a number of countries have fortified certain foods with iron. In Denmark, flour was fortified with iron from 1954 until 1987, at which time the mandatory fortification was stopped. This study examines the effect of iron fortification on iron status by comparing the intake of iron with serum ferritin over time and in relation to the removal of flour fortification. Methods. In a cohort of 238 Danish men and women, at baseline ages 35–65 years, dietary intake and serum ferritin were measured, first in 1987/1988 and again in 1993/1994. Results. In 1987/1988 the fortification may have supplied up to 25% of total iron intake, and without this enrichment some 35% of the men and 73% of the women may have had iron intakes lower than 10 mg/day. Assuming that no flour was enriched, iron intake was constant during the 6-year study period. Despite this, after flour fortification was stopped in 1987, serum ferritin increased among both men and postmenopausal women. Conclusions. Considering that mandatory iron fortification of flour affects the entire population, including subjects who are at risk for chronic diseases because of too-high iron stores, the decision to stop the mandatory fortification in Denmark seems to have been well-founded.