Ferrous lactate

Ferrous lactate is the iron(II) salt of lactic acid, used in food as a colour retention agent and iron supplement. Its primary food application is in the processing of ripe (black) olives, where it serves the same colour-fixing function as ferrous gluconate — reacting with tannins in the olive flesh to produce a stable, uniform dark colouration. Beyond olive processing, it appears in iron-fortified foods and dietary supplements as a gentle, bioavailable iron source. Lactic acid is itself a naturally occurring food component produced during fermentation, giving ferrous lactate a favourable chemical profile.

JECFA assessed ferrous lactate in 1965 alongside other iron salts and established an ADI of 0.8 mg/kg body weight per day, expressed as iron. This limit is based on the iron content of the additive rather than the lactate component, reflecting the regulatory approach to iron-containing additives as a class. Typical iron contribution from ferrous lactate in its food additive role is small, and dietary exposure from olive processing residues is negligible. Its use in supplementation contexts involves higher doses, but still within therapeutic iron ranges.

Ferrous lactate is approved in the EU as E585 and in other markets for olive processing and iron fortification. It is considered a well-tolerated iron source relative to inorganic iron salts like ferrous sulphate, with clinical evidence suggesting lower rates of gastrointestinal irritation at equivalent iron doses. Consumers with iron overload conditions — including hereditary haemochromatosis — should monitor total iron intake from all supplement and fortified food sources. For the general population, exposure from ferrous lactate in its typical food additive applications presents no health concern, and its presence in ripe olive products serves a purely cosmetic quality function.