Iron(II) glycinate refers to an iron complex of glycinate. Such species are transition metal amino acid complexes. Some compositions are used as dietary supplements and in food fortification in the place of other sources of iron, often under the trademark Ferrochel.United States Patent and Trademark Office. “FERROCHEL” trademark registration, Albion Laboratories, Inc. It is sometimes sold as a hydrochloride salt.
Structure The structure of one glycinate complex of iron(II) has been determined by X-ray crystallography. The octahedral complex features two bidentate glycinate ligands as well as two aquo ligands.
Synthesis Iron(II) glycinate is claimed to form when iron powder is treated with a two-fold molar excess of glycine in a citric acid solution. The citric acid acts as an antioxidant to prevent oxidation of Fe(II) to the more insoluble and therefore less bioavailable Fe(III) form:EFSA AFC Panel (2006). Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (AFC) related to ferrous bisglycinate as a source of iron for use in the manufacturing of foods and in food supplements. EFSA Journal 4(1):299, 1–17. doi:10.2903/j.efsa.2006.299.Food and Agriculture Organization of the United Nations. “Chemical and Technical Assessment: Ferrous Glycinate (Processed with Citric Acid).” Prepared for the Sixty-First Meeting of the Joint FAO/WHO Expert Committee on Food Additives (JECFA), first draft by Inge Meyland, 2004.
Commercial formulations retain the citric acid as a preservative, and include silicon dioxide (0.01%) and maltodextrin (2%).
Safety Since 2001, iron(II) glycinate has been generally regarded as safe by the Food and Drug Administration (FDA), with a No Observable Adverse Effect Level (NOAEL) of at least 500 mg kg−1 rat body weight. Compared to other iron salts, such as iron sulfate, it is associated with fewer adverse gastrointestinal effects and a higher bioavailability. For these reasons, it is a promising supplement for those with iron-deficiency anemia, and has shown significant increases in plasma ferritin, a protein that stores iron.
The European Food Safety Authority (EFSA) has evaluated ferrous bisglycinate for use in foods and supplements.
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