Non-anemic iron depletion, oral iron supplementation and indices of copper status in college-aged females

Objectives: Indices of copper status, specifically serum copper and ceruloplasmin concentrations and erythrocyte superoxide dismutase activity, and iron status, including serum ferritin, transferrin receptors, hemoglobin and hematocrit, were studied in 27 college-aged females with adequate iron versus low iron stores. Methods: Serum copper and ceruloplasmin concentrations, erythrocyte superoxide dismutase activity, serum ferritin, transferrin receptors, hemoglobin and hematocrit were studied in 15 females with non-anemic iron depletion before and after five weeks of iron supplementation and in 12 healthy iron-adequate females aged 19 to 28 years. Results: Mean hemoglobin, hematocrit and ferritin concentrations of the control group (144 +/- 11 g/L, 43 +/- 3% and 38 +/- 15 mug/L, respectively) were significantly higher than those of the iron depleted group prior to supplementation (134 +/- 9 g/L, 39 +/- 2% and 11 +/- 6 mug/L, respectively). The serum transferrin receptor to serum ferritin ratio was significantly greater for the iron depleted group prior to supplementation (890 +/- 753) versus the control group (151 +/- 61). Mean serum copper and ceruloplasmin concentrations and erythrocyte superoxide dismutase activity of the iron-adequate control group (20.0 +/- 5.7 mumol/L, 463 +/- 142 mg/L and 527 +/- 124 U/mL, respectively) were significantly higher than those of the iron depleted group (12.4 +/- 3.8 mumol/L, 350 +/- 108 mg/L and 353 +/- 186 U/mL, respectively) prior to supplementation. Following iron supplementation, hematocrit and ferritin concentrations of the iron depleted group significantly increased to 42 +/- 3% and 26 +/- 8 mug/L, respectively. Mean serum transferrin receptor concentrations and the serum transferrin receptor to ferritin ratios significantly decreased in the iron depleted group following supplementation (6.1 +/- 1.6 mg/L to 4.6 +/- 1.5 mg/L and 890 +/- 753 to 198 +/- 114, respectively). Iron supplementation also significantly increased the mean serum copper concentration to 14.2 +/- 5.4 mol/L and, in subjects with serum ferritin concentrations less than or equal to12 mug/L, the mean serum ceruloplasmin concentration. Conclusions: Non-anemic iron depletion characterized by low iron stores is associated with negative impacts on copper status. Iron supplements improved indices of iron status and serum copper and ceruloplasmin concentrations. Whether the diminished serum copper and ceruloplasmin concentrations and superoxide dismutase activity are associated with free radical damage to iron depleted cells requires further investigation.