To investigate the effects of body iron depletion and iron supplementation on serum lipid concentrations, hematologic indices, iron markers, and serum lipid profiles were measured in 427 girls, age 14-19 yr. There were no significant differences in serum lipid concentrations between subjects with moderate iron deficiency anemia (blood Hb < 12.0 g/dL) and healthy controls. However, serum total cholesterol concentration (mean +/- SD, 148 +/- 16 mg/dL) in severely anemic subjects with blood Hb < 8.0 g/dL was significantly lower than in subjects with blood Hb > or = 14.0 g/dL (170 +/- 17 mg/dL) (p < 0.01). Moreover, serum triglyceride concentration in subjects with blood Hb > 14.0 g/dL was 2-fold higher than in the severely anemic subjects. Mean values of serum total cholesterol and triglyceride (149 +/- 17 mg/dL and 58 +/- 22 mg/dL) in girls with severe anemia were significantly elevated after iron supplementation (164 +/- 17 mg/dL and 98 +/- 26 mg/dL) (p < 0.01, respectively). In the severely anemic subjects, blood Hb concentration was correlated with serum total cholesterol (r = 0.49, p < 0.01) and triglyceride concentrations (r = 0.51, p < 0.01). These findings indicate that severe iron deficiency anemia in girls is attended by decreased concentrations of serum total cholesterol and triglyceride, and that these reduced serum lipid levels return to normal following iron supplementation.