This site is intended for UK healthcare professionals
Medscape UK Univadis Logo
Medscape UK Univadis Logo

Ferrous sulfate and ascorbic acid

Updated 2 Feb 2023 | Oral iron

Drugs List

  • ascorbic acid 500mg and ferrous sulfate 325mg modified release tablet
  • FERROGRAD C controlled release tablet
  • Dosage


    1 tablet daily.


    No dosage adjustment necessary (see 'Dosage - Adults' section)


    Children 12 years and over
    1 tablet daily

    Children under 12 years
    Not recommended


    For oral administration.

    Tablets should be taken before food and swallowed whole.


    Intestinal obstruction
    Intestinal diverticular disease

    Repeated blood transfusions
    Concurrent parenteral iron therapy

    Children under 12 years

    Precautions and Warnings

    Exclude any serious underlying cause of anaemia before starting treatment.

    To be used with caution in the following :
    Inflammatory bowel disease - may exacerbate diarrhoea
    Elderly patients - constipation may lead to faecal impaction.

    Advise patient to keep out of reach of children .

    Advise patient that stools may be discoloured, black. This may interfere with tests used for detection of occult blood in the stools. The guaiac test occasionally yields false positive tests for blood.

    The inert tablet matrix will be excreted unchanged in the stools. This may represent a safety hazard in the elderly and others with delayed intestinal transit.

    Pregnancy and Lactation


    This medication is inappropriate in pregnancy for the prevention of neural tube defects as there is no folic acid contained in it. Folic acid supplementation is required pre-conception to the end of the first trimester.

    Plasma volume expansion during pregnancy results in a physiological decrease in haemoglobin concentrations which typically fall in the second trimester and then rise to approach pre-pregnancy levels at term. Mean Cell Volume (MCV) is unaffected during pregnancy and offers a better indicator of iron-deficiency anaemia. Iron treatment of low haemoglobin in the absence of other signs of deficiency is seldom required.

    Adverse outcomes in pregnancy such as low birth-weight, pre-term birth and perinatal death in states of mild to moderate anaemia have been found in studies, although the causality and also preventability by iron supplements remain unclear. Additionally, iron supplements have been shown to result in an increase in low birth-weight and pre-term delivery.

    Iron should be given if there is evidence of deficiency in the first trimester and later based on haemoglobin below 10g/dL or MCV below 82fL.

    Iron supplements should be considered in women with increased risk of iron deficiency anaemia such as those who have had recent menorrhagia, repeated closely spaced pregnancies or miscarriages and those with poor dietary intake.

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14-17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( ) or if this is unavailable at the backup site ( ).


    Ascorbic acid is excreted in breast milk but it is not known to be harmful to the infant.

    No adverse effects have been reported with ferrous sulfate in breast feeding. The use of relatively high doses in breast feeding mothers is probably not contraindicated, due to the fact that iron transports very poorly into the milk compartment.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at


    Advise patient to keep out of reach of children. Acute iron poisoning occurs rarely in adults, however, it could happen if children swallow this medication.

    Advise patient that spent matrix will be excreted in the stools.

    Inform patient that treatment might cause darkening of the stools.

    Advise patients not to take this medicine within one hour before or two hours after ingestion of the following medicines or food: antacids, calcium supplements, oxalates or phosphates, tea, coffee, milk or milk products, eggs or whole grains.


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Reference Sources

    British National Formulary, 62nd Edition (2011) Pharmaceutical Press, London.

    BNF for Children (2011-2012) Pharmaceutical Press, London.

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 2nd edition (2007) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Medications and Mothers' Milk, 14th Edition (2010) Hale, T. Hale Publishing, Amarillo, Texas.

    Summary of Product Characteristics: Ferrograd C Tablets. Teofarma S.r.l. Revised December 2005

    Therapeutics in Pregnancy and Lactation (2000) Lee, A., Inch, S. and Finnigan, D. Radcliffe Medical Press, Abingdon.

    Access the full UK drug database with a FREE Medscape UK Account
    It takes just a few minutes, and you’ll get unlimited access to information on over 11,000 UK drugs.
    Register for Free

    Already a member? Log in

    Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content

    FDB Logo

    FDB Disclaimer : FDB Multilex is intended for the use of healthcare professionals and is provided on the basis that the healthcare professionals will retain FULL and SOLE responsibility for deciding what treatment to prescribe or dispense for any particular patient or circumstance.