Ferrous fumarate with folic acid

How it works

Ferrous fumarate provides elemental iron for haemoglobin synthesis and replenishment of iron stores, while folic acid is reduced to tetrahydrofolate, a cofactor for DNA synthesis and erythropoiesis.

Prescribing in practice

• The folic acid content is intended for routine antenatal supplementation and does not provide the higher dose needed for women at increased risk of neural tube defects, who require a separate high-strength folic acid product.
• Oral iron commonly causes gastrointestinal upset, constipation or dark stools, which can affect adherence; taking it with or after food and adjusting frequency may improve tolerability.
• Iron reduces absorption of several drugs including levothyroxine, bisphosphonates and certain antibiotics such as tetracyclines and quinolones, so doses should be separated.

Monitoring

Monitor the haemoglobin and, where relevant, iron indices to confirm an adequate response and guide duration of treatment.

Counselling the patient

• Stools may turn black, which is harmless, but seek advice if you have severe abdominal pain or persistent vomiting.
• Keep well out of the reach of children, as iron overdose is dangerous to young children.
• Separate this from indigestion remedies, calcium and certain other tablets by a couple of hours.

Evidence & guidelines

NICE antenatal care guidance supports folic acid supplementation in pregnancy and treatment of iron-deficiency anaemia, while reserving routine universal iron supplementation for those with demonstrated need.