The aim of the present study was to evaluate the influence of menstruation, method of contraception, and iron supplementation on iron status in young Danish women, and to assess whether iron deficiency could be predicted from the pattern of menstruation. Iron status was examined by measuring serum (S-) ferritin and hemoglobin (Hb) in 268 randomly selected, healthy, menstruating, nonpregnant Danish women aged 18-30 years. Iron deficiency (S-ferritin <16 microg/l) was observed in 9.7%, of the women, iron deficiency anemia (S-ferritin < 13 microg/l and Hb < 121 g/l) in 2.2%. Iron supplementation, predominantly as vitamin-mineral tablets containing 14-20 mg of ferrous iron was used by 35.1%. The median serum ferritin was similar in non-iron users and in iron users, whereas the prevalence of iron deficiency was 12.6% in nonusers vs. 4.3% in users, the prevalence of iron deficiency anemia 3.4% in nonusers vs. 0%, in users (p=0.17) In non-iron-supplemented women, S-ferritin levels were inversely correlated with the duration of menstrual bleeding (rs= -0.25, p<0.001) and with the women's assessment of the intensity of menstrual bleeding (r(s)= -0.27, p<0.001), whereas no such correlations were found in iron-supplemented women. The results demonstrate that even moderate daily doses of ferrous iron can influence iron status in women with small iron stores. Women using hormonal contraceptives had menstrual bleeding of significantly shorter duration than those using intrauterine devices (IUD) or other methods. There was a high prevalence of small and absent body iron stores in young women, suggesting that preventive measures should be focused on those women whose menstruation lasts 5 days or longer, who have menstrual bleeding of strong intensity, who use an IUD without gestagen, and who are blood donors.
PIP: The influence of menstruation, method of contraception, and low-dose iron supplementation on iron status was investigated in 268 randomly selected, healthy, nonpregnant women 18-30 years of age from Copenhagen, Denmark. In addition, risk factors for development of iron deficiency in fertile women were identified. Iron deficiency (serum ferritin 16 mcg/l) was present in 9.7% and iron deficiency anemia (serum ferritin 13 mcg/l and hemoglobin 121 g/l) in 2.2%. 94 women (35.1%) took iron supplements, generally as a vitamin-mineral tablet containing 14.20 mg of ferrous iron. Median serum ferritin was the same (39 mcg/l) in users and non-users of iron supplements; however, the prevalence of iron deficiency was 12.6% in non-users compared with 4.3% in users and that of iron deficiency anemia was 3.4% in non-users vs. 0% in users. In non-users of iron supplements, serum ferritin levels were inversely correlated with the duration of menstrual bleeding (p 0.001) and women's assessment of the intensity of their bleeding (p 0.001). No such associations were found in supplement users. Menstrual bleeding in women using hormonal contraception (mean, 4.8 days) was significantly shorter than in those using IUDs (mean, 5.7 days). Median ferritin levels were 40 mcg/l in oral contraceptive users and 38 mcg/l in IUD users. Median serum ferritin levels also were higher in women who were not blood donors than in the 40 women (14.9%) who were regular donors (40 mcg/l and 30 mcg/l, respectively). These findings suggest that preventive measures should focus on women whose menstruation lasts 5 days or more, who have menstrual bleeding of strong intensity, who use an IUD without gestagen, and who are blood donors. These women should be encouraged to consume a diet rich in iron with a high bioavailability and/or to take a daily tablet containing 14-20 mg of ferrous iron.