Iron status including S-ferritin and haemoglobin (Hb) was assessed in a population survey comprising 1433 Danish males in age cohorts of 30, 40, 50 and 60 years. There was no significant difference in S-ferritin levels between the age groups. In the entire series, median S-ferritin was 126 micrograms 1-1, 5-95% tile 31-378 micrograms 1-1, range 5-3600 micrograms 1-1; 1.2% had values less than 15 micrograms 1-1 (i.e. depleted iron stores), 3.7% values from 15-30 micrograms 1-1 (i.e. small iron stores), and 95.1% values greater than 30 micrograms 1-1 (i.e. replete iron stores); 73.8% had values from 61-300 micrograms 1-1, and 9.5% values greater than 300 micrograms 1-1. Blood donors had lower S-ferritin than non-donors and a higher frequency of depleted iron stores (p less than 0.0001). Hb values showed no age variation; median values was 155 g 1-1 (9.6 mmol 1-1), 5-95% tile 137-171 g 1-1 (8.5-10.6 mmol 1-1). Hb values less than 129 g 1-1 (8.0 mmol 1-1) were observed in 1.7%, and values less than 121 g 1-1 (7.5 mmol 1-1) in 0.8%. Males with S-ferritin less than 15 micrograms 1-1 (n = 17) had lower Hb, median 148 g 1-1 (9.2 mmol 1-1), than those with S-ferritin greater than or equal to 15 micrograms 1-1, median 155 g 1-1 (9.6 mmol 1-1) (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)