Iron has a variety of important roles in your health and wellbeing, and one of its key functions is in developing red blood cells which carry oxygen around your body. It is also an essential component in many enzyme reactions and helps your immune system function at its best. (1)
In adults, around 70% of the body’s Iron is found in haemoglobin molecules in red blood cells that enable oxygen to be carried in your blood from your lungs to the tissues, so it plays a vital role in humans. (2)
Are women getting enough Iron?
Research shows the average dietary intake of Iron is lower among women than men. Over a quarter (27%) of women aged 19-64 years and almost half (48%) of girls (aged 11-18 years) may have an inadequate intake of Iron. (3)
In comparison, just 1% of adult men and 9% of teenage boys are likely to have an inadequate intake of Iron. (3)
Symptoms of Iron deficiency
When your body doesn’t have enough Iron, your blood will lack adequate healthy red blood cells which carry oxygen to the body’s tissues. Some of the common symptoms of Iron deficiency include tiredness, shortness of breath, noticeable heartbeats (heart palpitations) and pale skin.
Iron deficiency anaemia can be caused by blood loss from the stomach and intestines, which may be due to stomach ulcers, piles, inflammatory bowel disease or taking non-steroidal anti-inflammatory drugs such as ibuprofen and aspirin. (4)
Blood loss due to heavy periods is the most common cause of Iron deficiency in women of childbearing age.
Why women are more at risk of iron deficiency
Heavy menstrual periods
Heavy periods (also known as menorrhagia), are a common complaint among women. The prevalence increases with age, peaking in women aged 30-49 years. 1 in 20 women aged 30-49 years in the UK consult their GP each year about heavy periods. (5) It is difficult to measure blood loss accurately, and the perception of what is ‘heavy’ menstrual bleeding is subjective. In some studies assessing menstrual blood loss, the prevalence of heavy periods ranged from 20-52% based on subjective assessment. (6) Periods are considered ‘heavy’ if they are interfering with a woman’s quality of life and causing problems. (5)
There are no recommendations for increasing Iron intake during pregnancy as the extra demand should be met from existing body stores and lack of menstrual blood loss. It is also thought that a woman’s body when pregnant, and breastfeeding, adapts to ensure the baby receives adequate supply of Iron, even when the mother is Iron deficient. However some pregnant women may develop low Iron status so plenty of Iron-rich foods should be eaten. You can learn more about Iron rich foods here.
It can take several months for a woman to replenish her Iron stores after a pregnancy and some studies suggest leaving a gap of 18 months between pregnancies to enable nutrient stores to replenish. (2,7)
How much iron do you need?
Men and women have different requirements for Iron. From the onset of menstruation until monthly periods stop, after the menopause, women need almost twice as much Iron as men. This is because a woman's monthly period can use up the body’s Iron reserves, especially if dietary Iron is low or if a woman has heavy periods.
The Recommended Nutrient Intake (RNI) for children aged 7-10 years is 8.7mg a day. The adolescent growth spurt leads to an increase in blood volume, haemoglobin and muscle tissue, so iron requirements also increase. The RNI is 11.3mg a day for boys and 14.8mg a day for girls aged 11-18 years.(2)
Among adults (aged 19-50 years) the RNI is 8.7mg a day for men and 14.8mg a day for women. From age 50+ years requirements for both men and women are the same, with the RNI of 8.7mg a day.(2)
Want to learn more? Discover the best dietary sources of Iron here.
By Dr Laura Wyness, PhD, RNutr
- EU Register of nutrition and health claim made on foods (2016). Available: https://ec.europa.eu/food/safety/labelling_nutrition/claims/register/public/?event=register.home
- SACN (2010) Iron and Health. Available: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/339309/SACN_Iron_and_Health_Report.pdf
- NDNS (2018) NDNS results from years 7 and 8 (combined). Available: https://www.gov.uk/government/statistics/ndns-results-from-years-7-and-8-combined
- NHS Choices (2018) Iron deficiency anaemia. Available: https://www.nhs.uk/conditions/iron-deficiency-anaemia/
- NICE (2018) Menorrhagia. Available: https://cks.nice.org.uk/topics/menorrhagia/
- Lethaby et al (2015) Progesterone or progestogen-releasing intrauterine systems for heavy menstrual bleeding. Available: https://pubmed.ncbi.nlm.nih.gov/25924648/
- BNF (2013). Nutrition and Development: short and long-term consequences for health. Available: https://www.nutrition.org.uk/attachments/599_Q_A%20chapter.pdf