A preparation is disclosed that comprises one or more iron(III) complex compounds which have a redox potential at pH 7 of from −324 mV to −750 mV relative to a normal hydrogen electrode (NHE), and one or more redox-active substances, wherein the carbohydrates are selected from the group consisting of dextrans and hydrogenated dextrans, dextrins, oxidised or hydrogenated dextrins, as well as pullulan, oligomers thereof and/or hydrogenated pullulans, and wherein the redox-active substance(s) is/are selected from the group consisting of ascorbic acid； vitamin E； cysteine； physiologically acceptable phenols/polyphenols selected from the group consisting of quercetin, rutin, flavones, flavonoids, hydroquinones； and glutathione, and in particular is ascorbic acid.
