Iron status in Danish women aged 35-65 years. Relation to menstruation and method of contraception.

Iron status was assessed by serum (S-) ferritin and hemoglobin (Hb) in a population survey comprising 883 non-gravid Danish women in age cohorts of 35, 45, 55, and 65 years. Premenopausal women (n = 676) had lower S-ferritin, median 42 micrograms/l, than postmenopausal women (n = 207), median 80 micrograms/l (p < 0.0001). Of premenopausal women, 12.1% had S-ferritin < or = 20 micrograms/l (i.e. depleted iron stores), and 35.6% S-ferritin of 21-40 micrograms/l (i.e. small iron stores). Corresponding figures in postmenopausal women were 0.5% and 13.2%. Premenopausal blood donors (n = 88) had lower S-ferritin than non-donors (p < 0.001). In premenopausal women, S-ferritin levels were strongly dependent on the duration of menstrual bleeding (p < 0.0001), which in turn was related to the method of contraception. Women (n = 64) using hormonal contraceptives (the pill) had menstrual bleeding of shorter duration than those (n = 511) not using pills or intrauterine devices (IUD), who in turn had bleeding of shorter duration than those (n = 101) using IUD. Median S-ferritin in pill users was 62 micrograms/l, in those not using pills or IUD 42 micrograms/l, and in IUD users 36 micrograms/l. S-ferritin values < 40 micrograms/l (i.e. small and depleted iron stores) were seen in 25% of pill users, in 48% of those not using pills or IUD, and in 61% of IUD users.(ABSTRACT TRUNCATED AT 250 WORDS)