Ferrous Fumarate - how long should a person be taking ferrous fumerate.-210mg 3 times a day?

* For treating anemia due to insufficient iron (iron-deficiency anemia) in adults: 50-100 mg elemental iron is given three times daily. For children with iron deficiency anemia: the dose is 4-6 mg/kg per day divided into three doses. Treatment is usually continued 6 months to build up the body’s iron reserves. Two to three months of treatment may reverse anemia without rebuilding the supply of stored iron. Iron deficiency due to ongoing uncontrolled bleeding requires continuous iron therapy.

* For improving thinking skills in iron-deficient adolescents: 650 mg ferrous sulfate twice daily.

* For reducing cough associated with a class of blood pressure medicinces called angiotensin converting enzyme (ACE) inhibitors: 256 mg ferrous sulfate daily.

https://www.drugs.com/drug-interactions/ferrous-sulfate.html

Hope the info is of help to you? However it would be better to seek medical help, best of luck!