Recovery of Hb and iron parameters from blood donation. (A) Iron kinetics after whole blood donation for 49 whole blood donors. The vertical bold line indicates day 57, the minimum required interval between 2 donations in the Netherlands. (B) Percentage of donors back at baseline levels (±2 × standard deviation [SD], in which SD = [biological + analytical coefficient of variation %] of the baseline concentration; supplemental Table 5). Solid lines indicate regular donors, and dashed lines new donors. Bold lines in panel A are the mean values for each of the groups. Mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, red cell distribution width, iron, transferrin saturation (TSAT), and zinc protoporphyrin showed no significant changes in time after blood donation and were therefore not included in this figure. Hb (mmol/L) × 1.611 = Hb (g/dL).