Iron(II) fumarate, also known as ferrous fumarate, is the iron(II) salt of fumaric acid, occurring as a reddish-orange powder, used to supplement iron intake. It has the chemical formula C4H2FeO4. Pure ferrous fumarate has an iron content of 32.87%, therefore one tablet of 300 mg iron fumarate will contain 98.6 mg of iron (548% Daily Value based on 18 mg RDI).
Ferrous fumarate is often taken orally as an iron supplement to treat or prevent iron deficiency anemia.[1] Mixtures of ferrous fumarate and potassium iodate, "double fortified salt", are used to address both iron and iodine deficiencies.[2]