A week after the blood donation, donors with a ferritin level <30 ng/ml and hemoglobin > 120g/l (non anaemic) will be included in the study and randomised. A one-month iron treatment vs placebo will be introduced. To assess the subjective response on fatigue, the donors will fill in different questionnaires at the time of the blood donation and then after a week, a month and 3 months.