The importance of adequate iron intake during the teenage years

With 49 per cent of girls aged 11 to 18 shown to have low iron intakes (below the LRNI) perhaps it is time for a public health campaign to improve iron intakes among teenagers. As these girls lay down the foundations of dietary habits for their adult lives, iron adequacy will be important in pregnancy as well as in general health throughout menstruation. Teenage boys too have increased requirements compared with younger children, so also need support to improve intakes. In this article, iron requirements, deficiency and crucially the prevention of deficiency will be examined. This article complements the NHD fact file on Iron Deficiency.

Iron is an essential mineral for health. It is vital for producing haemoglobin, the iron-containing protein in red blood cells which transports oxygen to cells around the body. (1) Iron is also needed for DNA synthesis and electron transport. (2) During puberty there is an increased demand for iron as the body grows and develops, particularly as blood volume increases, lean mass increases and, in the case of females, menstruation commences.

That is why iron deficiency has been highlighted in a recent NHD fact-file which includes screening, diagnosis, and both medical and dietetic treatment. (3) This article will give an overview and then focus more on prevention of iron deficiency.

Iron requirements for teenagers

Whilst requirements vary, the RNIs for iron show that there is a big increase in requirements in the pre-teen and teenage years – see Table 1. This increase is not regularly discussed among the public and there are no specific national public health campaigns in the UK to focus on raising awareness of this. Whilst the recommended portions of food increase on the School Food Standards (for school meals) there is no specific focus on increasing iron rich foods in the secondary years. (5)The School Food Standards do list suggestions as to ways to increase iron intake but there is no mandatory obligation to provide a certain level of iron. The number of iron rich foods is also not mandated to be increased in the secondary meals, compared with primary meals.

Table 1 - iron requirements

Age

Males

Females

7-10 years

8.7mg

8.7mg

11-18 years

11.3mg

14.8mg

19 +

8.7mg

14.8mg until menopause, 8.7mg post menopause

Deficiency – impact and symptoms

The impact of deficiency can be very problematic for teenagers and can easily be missed. Tiredness may be put down to a busy school schedule or staying up late, so deficiency may not be identified quickly. Tiredness and headaches can impact school attendance and concentration in class, which could impact attainment long term.

Symptoms of iron deficiency anaemia are shown in table 2 below. (6)

Table 2 - symptoms of iron deficiency anaemia

Common symptoms

Less common symtoms

  • Tiredness and lack of energy

  • Shortness of breath

  • Noticeable heartbeats (heart palpitations)

  • Paler than usual skin

  • Hearing ringing, buzzing or hissing noises inside your head (tinnitus)

  • Food tasting strange

  • Feeling itchy

  • A sore tongue

  • Hair loss

  • Wanting to eat non-food items, such as paper or ice (pica)

  • Finding it hard to swallow (dysphagia)

  • Painful open sores (ulcers) in the corners of your mouth

  • Nail changes, such as spoon-shaped nails

  • Restless legs syndrome

Raising awareness of these symptoms amongst teenagers, parents, teachers and youth leaders is important to support the identification of possible cases of deficiency.

Common causes of iron deficiency in teenagers

As children get older, they are often given more independence when it comes to food choices. The food available at schools also tends to have more meal-component options rather than the standard 2-3 meal options in primary school. Peer pressure and the desire to make their own choices, alongside limited options for iron rich foods, can lead to poorer diets, increasing the risk of iron deficiency.

As mentioned above, the increased needs can also result in deficiency if intake does not increase to match the requirements. This is particularly true in girls where the requirements significantly increase. According to the latest National Diet and Nutrition Survey (NDNS) data, forty-nine per cent of girls aged 11 to 18 years had low iron intakes (below the LRNI). (7)

Lifestyle factors such as sports and following vegetarian or vegan diets can also increase the risk of deficiency. Sport can increase the demand for iron due to the lean mass synthesis which may occur. Alongside sport, teenagers may not have access to good quality sports nutrition information – either being given information tailored more to adults who do not need to factor in the continued growth requirements, or they access poor quality nutrition information which focuses more on protein (often, anecdotally in the form of chicken, eggs and protein powder) and carbohydrates (including sports drinks and gels) than the balanced diet as a whole.

Teenagers experimenting with vegetarian or vegan diets may not have the knowledge about how to ensure adequacy on these diets, or understand how to improve absorption of iron. They may also not like certain foods so that may further limit their possible intake of iron rich foods.

Prevention of iron deficiency

1.       Raise awareness of need for iron rich foods

All those involved in the care and education of children and adolescents are encouraged to discuss iron intake. Iron intake is important throughout adulthood too so, for those who have not established good intake before reaching adulthood, they also need information. This could be done through a variety of methods including through social media and school education. Awareness raising should also include iron adequacy on a vegetarian or vegan diet.

2.       Boost iron intake

Increasing availability of iron rich foods to young people is essential as well as addressing some of the challenges, including fussy eating and dietary preference. Availability of foods includes in schools and home settings, but also there is scope to work with the out of home sector to also increase intake.

Table 3 shows iron per 100g and per portion in certain foods. (8)

Table 3 - iron per 100g per portion of foods

Food/s

Iron per 100g (g)

Portion size

Iron per portion

Extra lean beef mince, stewed

1.5

100g

1.5

Beef, stewing steak, stewed, lean

2.6

100g

2.6

Salmon, wild, grilled

0.6

140g

0.8

Tuna, canned in sunflower oil, drained

1.19

1 can (102g drained weight)

1.2

Sardines, canned in olive oil, drained

2.3

140g

3.2

Almonds, whole kernels

3.71

30g

1.1

Breakfast cereal, wheat biscuits, Weetabix type, fortified

11.9

2 biscuits (38g)

4.5

Breakfast cereal, bran flakes, fortified

13.5

30g

4.1

Beans, red kidney, canned in water, re-heated, drained

2.26

80g

1.8

Lentils, red, split, dried, boiled in unsalted water

2.14

80g

1.7

Peas, frozen, microwaved

1.75

80g

1.4

Broccoli, green, steamed

0.75

80g

0.6

The table above emphasises the benefit of having a fortified breakfast cereal. With up to 30% of young people not eating breakfast. this is perhaps an area to focus on. (9) With the introduction of breakfast clubs available for all primary school children in England and Wales, perhaps further evidence can be gathered about the impact on iron intake – if indeed fortified cereals are used.

The iron fact file includes some meal suggestions for boosting intake.

3.       Boosting Iron Absorption

Absorption is another factor which needs to be considered. Consuming iron rich foods alongside vitamin C can increase absorption whereas phytates, calcium and tannins can reduce absorption. (10) Tea drinking may also be a cultural dietary preference and so education in this area needs to be done sensitively.

Depending on iron stores in the body between 15% to 35% of haem iron is absorbed, whereas non haem iron has a lower absorption rate of 2% to 20%. (11)

4.       Role of supplements

Whilst supplements can be helpful for those who have already developed deficiency, they are not recommended for all children. Supplements may also be needed for children with very restricted diets however a full nutritional assessment is recommended before supplements are given in order to ensure nutritional adequacy across the spectrum. Taking too much iron can cause constipation, nausea, sickness and stomach pain. In very high doses it can be fatal. (12)

NEW dietary information database table!

Easily access important nutritional information in a table format to aid in your work or studies.

Summary

Adequate iron intake and stores are essential for health. As requirements increase in adolescence, care needs to be taken to ensure teenagers consume enough iron rich foods and boost absorption.

Written exclusively for NHD by...

References

  1. Gell D. A. (2018). Structure and function of haemoglobins. Blood cells, molecules & diseases70, 13–42. https://doi.org/10.1016/j.bcmd.2017.10.006 https://pubmed.ncbi.nlm.nih.gov/29126700/

  2. Abbaspour, N., Hurrell, R., & Kelishadi, R. (2014). Review on iron and its importance for human health. Journal of research in medical sciences : the official journal of Isfahan University of Medical Sciences19(2), 164–174. https://pmc.ncbi.nlm.nih.gov/articles/PMC3999603/

  3. NHD (2025) NHD PAEDIATRIC HUB FACT FILE

    Iron deficiency anaemia. https://www.nhdmag.co.uk/paediatric-hub/fact-file/iron-deficiency-anaemia

  4. British Nutrition Foundation (2021) Nutrition Requirements. Accessed at https://www.nutrition.org.uk/media/nmmewdug/nutrition-requirements.pdf on 15th January 2025

  5. Department for Education (2024) Guidance: School food standards practical guide: Updated 19 September 2024. Accessed at:

    https://www.gov.uk/government/publications/school-food-standards-resources-for-schools/school-food-standards-practical-guide on 15th January 2025

  6. NHS (2024) Iron deficiency anaemia. Last updated 26th January 2024. Accessed at: https://www.nhs.uk/conditions/iron-deficiency-anaemia/ on 15th January 2025

  7. Public Health England (2020) https://www.gov.uk/government/statistics/ndns-results-from-years-9-to-11-2016-to-2017-and-2018-to-2019/ndns-results-from-years-9-to-11-combined-statistical-summary#:~:text=Forty%2Dnine%20per%20cent%20of,and%202%25%20of%20older%20women

  8. Quadram Institute Bioscience (2025) Food and Nutrition - NBRI extended dataset based on PHE's McCance and Widdowson's Composition of Foods Integrated Dataset https://quadram.ac.uk/UKfoodcomposition/ Accessed 15th January 2025

  9. Gibson-Moore, H. et al (2023) REVIEW: No food for thought–How important is breakfast to the health, educational attainment and wellbeing of school-aged children and young people? Nutrition Bulletin. Volume 48, Issue4 December 2023. Pages 458-481 First published: 20 November 2023https://onlinelibrary.wiley.com/doi/epdf/10.1111/nbu.12652

  10. Ems T, St Lucia K, Huecker MR. Biochemistry, Iron Absorption. [Updated 2023 Apr 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK448204/

  11. Monsen E. R. (1988). Iron nutrition and absorption: dietary factors which impact iron bioavailability. Journal of the American Dietetic Association88(7), 786–790. https://pubmed.ncbi.nlm.nih.gov/3290310/

  12. NHS (2020) Iron. Last reviewed: 03 August 2020. Accessed at: https://www.nhs.uk/conditions/vitamins-and-minerals/iron/ on 16th January 2025


Share


Comments

Leave a comment on this post

Thank you for for the comment. It will be published once approved.
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.