Iron status in 358 apparently healthy 80-year-old Danish men and women: relation to food composition and dietary and supplemental iron intake

Abstract

In Denmark, the intake of dietary iron has decreased since 1987, when the mandatory iron fortification of flour (30 mg carbonyl iron/kg) was stopped. Since there have been no studies of iron status in elderly Danes after the abolishment of iron fortification, there is a need to assess actual iron status in the elderly population. The objective was to evaluate iron status and the relationship with food composition and dietary and supplemental iron intake in an elderly population in Copenhagen County. Participants in this health examination survey were 358 subjects (171 men, 187 women) 80 years of age from a 1914 cohort study. Blood samples included serum ferritin and hemoglobin (Hb). A dietary survey was performed in 232 subjects (120 men, 112 women) using a dietary history method. Median serum ferritin was 100 microg/l in men and 78 microg/l in women ( p<0.001). Ferritin concentrations <16 microg/l (i.e., depleted iron stores) were found in three men (2%) and in ten women (5%). Median Hb was 140 g/l in men and 131 g/l in women ( p<0.001). Three subjects (0.84%) had iron deficiency anemia (i.e., ferritin <13 microg/l and Hb <5th percentile for iron-replete subjects (121 g/l in men, 114 g/l in women). Ferritin concentrations >300 microg/l (i.e., iron overload) were found in 15 (9%) men and in 5 (3%) women. Median dietary iron intake was higher in men (8.7 mg/day) than in women (7.3 mg/day) ( p<0.001). Serum ferritin was positively correlated to dietary intake of iron, meat, and alcohol and to body mass index in men. Serum ferritin displayed a negative correlation to the consumption of tea. The use of vitamin-mineral supplements containing iron had no influence on iron status. Dietary intake of iron and/or the bioavailability of dietary iron were adequate to maintain a favorable iron status in 80-year-old subjects displaying a low prevalence of iron deficiency and a moderate prevalence of iron overload.