Iron infusions and iron supplements: benefits and potential side effects

Healthylife Pharmacy25 February 2015|4 min read

Iron deficiency is the most common nutritional deficiency globally, leading to many people taking iron supplements. This article provides information about iron supplements and iron infusions, as well as potential benefits and side effects.

What causes low iron levels?

People may have low iron levels for a number of reasons, such as:

  • Poor absorption 
  • An inability to absorb iron properly into the body. This may occur due to intestinal damage (such as in celiac disease) or if part of the stomach or small intestine has been removed).
  • Heavy menstrual bleeding. 
  • Internal bleeding, for example due to gastrointestinal ulcers.
  • A lack of iron in food (particularly common in small children, pregnant women and teens).

When is an iron infusion needed?

An iron infusion, or ‘parenteral iron therapy’, is administered intravenously or intramuscularly and is often given as a secondary line treatment when oral supplements have failed or cannot be given for a particular reason. This may include:

  • Oral therapy produces severe side effects in patients that prevents their ongoing administration.
  • Oral therapy is not a viable option, i.e. the patient cannot swallow.
  • Immediate improvement in iron levels is required (such as before elective surgery).
  • Immediate improvement in haemoglobin levels is required (such as post-operative and post-transfusion).
  • Patients with underlying medical conditions where oral administration is not tolerated (such as inflammatory bowel disease or kidney conditions).

There are some circumstances in which iron infusions cannot be given, such as the first trimester of pregnancy. In general, iron infusions are not offered as a first-line treatment due to their cost and invasive nature.

What are the side effects of iron infusions?

Some individuals may experience side effects from an iron infusion, such as headache, nausea, vomiting, fever or dizziness. If you have specific concerns, it’s important to discuss them with your healthcare professional.

How are iron supplements taken?

Iron is often taken orally as a first-line treatment option and is available in a  number of forms. The most common form is iron (II) sulphate (also known as ferrous sulphate) and a wide range of other salts, including gluconate and carbonyl iron. 

Ferrous bisglycinate is another popular form. One study in pregnant women showed that it was better absorbed and resulted in fewer gastrointestinal side effects. More research on other populations is needed.

Vitamin C (ascorbic acid) may be included to aid better iron absorption.

Speak with your healthcare professional for advice on the best form of iron supplement to take and when you should take it. 

Potential side effects of iron supplements

Oral iron therapies are known to cause a number of adverse side effects. Constipation may be associated with taking iron supplements, as well as diarrhoea, abdominal cramping/pain, metallic taste in the mouth or in rare cases, allergic reactions.  Everyone is different, so it’s important to discuss with your healthcare professional so they can select the best option for you.

Why is my body not absorbing iron supplements? 

Certain iron supplements, when taken in conjunction with a number of other supplements, may decrease the absorption of both iron and other medications when taken at the same time. Your healthcare professional can provide more guidance on the type and timing of your iron supplement.

Related reads:

References

  1. Kumar, A., Sharma, E., Marley, A., Samaan, M. A., & Brookes, M. J. (2022). Iron deficiency anaemia: Pathophysiology, assessment, practical management. BMJ Open Gastroenterology, 9(1), e000759. https://doi.org/10.1136/bmjgast-2021-000759
  2. Lucas, S., & Garg, M. (2023). Intravenous iron: an update. Internal Medicine Journal. https://doi.org/10.1111/imj.16184
  3. Nguyen, M. (2023, July 3). Iron supplementation. StatPearls - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK557376/
  4. Cançado, R. D., & Múñoz, M. (2011). Intravenous iron therapy. Revista Brasileira De Hematologia E Hemoterapia, 33(6), 461–469. https://doi.org/10.5581/1516-8484.20110123
  5. Nguyen, M. (2023b, July 3). Iron supplementation. StatPearls - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK557376/
  6. Hetzel, D., Strauss, W., Bernard, K., Li, Z., Urboniene, A., & Allen, L. F. (2014). A Phase III, randomized, open-label trial of ferumoxytol compared with iron sucrose for the treatment of iron deficiency anemia in patients with a history of unsatisfactory oral iron therapy. American Journal of Hematology, 89(6), 646-650. https://doi.org/10.1002/ajh.23712
  7. Nguyen, M. (2023c, July 3). Iron supplementation. StatPearls - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK557376/
  8. Stoffel, N. U., Von Siebenthal, H. K., Moretti, D., & Zimmermann, M. (2020). Oral iron supplementation in iron-deficient women: How much and how often? Molecular Aspects of Medicine, 75, 100865. https://doi.org/10.1016/j.mam.2020.100865
  9. Tay HS, Soiza RL (2015). Systematic review and meta-analysis: what is the evidence for oral iron supplementation in treating anaemia in elderly people? Drugs Aging 32(2):149-58
Spread the word

This article is for informational purposes only and does not provide medical advice, diagnosis, or treatment. Any information published on this website or by this brand is not intended as a substitute for medical advice. If you have any concerns or questions about your health you should consult with a health professional.