Two iron compounds commonly used in dietary supplements and as food additives – ferric citrate and ferric EDTA – raise the level of biomarkers for colon cancer, according to a study conducted at Chalmers University of Technology in Sweden. A third iron compound, ferrous sulphate, did not have this effect.
The researchers examined the effects of typical supplemental doses of the iron compounds on two types of colon cancer cells. They discovered that ferric citrate and ferric EDTA increased levels of amphiregulin, a cancer biomarker associated with long-term disease and a poor prognosis, and might be carcinogenic.
About 20 different iron compounds are widely used as supplements and additives, but many product labels don’t identify which type of iron compound they contain. If you need an iron supplement, talk to your health care provider about which type to use.