Iron and periods: A guide for teen girls and families

Learn why iron needs rise for teen girls once periods start, spot low iron signs, and discover iron-rich foods to support energy. A guide for families.

Iron intake becomes a bigger consideration once periods begin. According to the Australian Bureau of Statistics Usual Nutrient Intakes 2023 release, 37.2% of females aged 12 to 17 have iron intakes below the Estimated Average Requirement, indicating that dietary intake may be insufficient to meet requirements for a substantial proportion of teenage girls, compared with 9.5% of males the same age. Growing bodies, higher activity levels and monthly blood loss all shift iron needs upward during the teenage years.

This article looks at why iron matters for teenage girls, how periods can affect iron levels, what parents and teens may notice at home, and the everyday steps that help support healthy iron intake through food. This article helps parents and teens navigating this stage together, with practical information to take to a GP if a closer look is needed.

Why iron matters for teenage girls

Iron is an essential mineral involved in transporting oxygen through the blood, supporting normal energy production, and contributing to healthy immune and cognitive function. Healthdirect explains that the body uses iron to make haemoglobin, the protein in red blood cells that carries oxygen from the lungs to the cells throughout the body.

For teenage girls, iron requirements climb sharply through adolescence. The Healthdirect guide to iron needs sets the Recommended Dietary Intake (RDI) for girls aged 14 to 18 at 15 mg per day, higher than the 11 mg per day set for boys of the same age. According to the NHMRC's Nutrient Reference Values for iron, the higher RDI from age 14 reflects the assumption that girls under 14 do not menstruate, while girls aged 14 and over do.

Meeting this daily amount isn't always straightforward. Iron can compete with other nutrients for absorption, and dietary patterns during the teenage years often include less red meat and fewer iron rich meals than at earlier or later stages of life.

How periods can affect iron needs

Menstruation involves the regular loss of blood, and blood carries iron. This is one reason why iron requirements are higher for females once periods begin.

For teens with heavier or longer periods, iron losses can add up over time. The Nutrition Australia iron fact sheet explains that women in their reproductive years have much higher iron requirements than men because of monthly blood loss and can find it hard to meet daily iron needs from food alone.

The teenage years are also when eating patterns can be less consistent. Missed meals, changing food preferences, restrictive eating, or vegetarian and vegan diets can each influence iron levels and may need extra support to keep intake on track.

Signs that may be associated with low iron

Low iron doesn't always show up as obvious signs. When it does, it often appears as general changes in energy or mood rather than anything specific.

Symptoms that may be associated with low iron include:

• Feeling fatigued or weak
• Shortness of breath, dizziness or feeling light-headed
• Reduced performance at school, sport or everyday activities
• Difficulty concentrating or focusing
• Pale skin
• Irritability or behaviour changes

Healthdirect also notes that various other conditions can cause these same symptoms. Late nights, exam stress, viral illness, low sleep quality and dehydration can all produce similar effects. Signs alone are not enough to identify low iron.

For parents, changes worth mentioning to a GP might include ongoing tiredness that doesn't lift with rest, a drop in performance or concentration in sport or at school, or a teen mentioning they've felt "off" for weeks at a time.

Heavy periods and when they may need checking

Periods vary from person to person, and what feels "heavy" for one teen may be typical for another. Healthdirect describes heavy menstrual bleeding as excessive blood loss that interferes with everyday life, and notes that about 1 in 4 females experience heavy periods.

Signs that a period may be considered heavy and worth a conversation with a GP include:

• Needing to change a pad or tampon every 1 to 2 hours
• Needing to change a pad or tampon overnight
• Bleeding for more than 8 days
• Passing blood clots larger than a 50-cent coin
• Bleeding through clothing
• Not being able to do things you normally would during your period

Alongside heavy bleeding, some people also feel very tired, look pale, have cramps in the lower abdomen, or feel short of breath.

Healthdirect also notes that puberty is a time when hormones are changing, and hormone imbalance can lead to anovulatory cycles (where an egg is not released during the menstrual cycle), which may cause heavy periods in teenagers and adolescents. Ongoing heavy bleeding is still worth checking with a GP.

Iron rich foods for growing teens

Food is the foundation of healthy iron intake. Iron in food comes in two forms: haem iron from animal sources and non-haem iron from plants. The Nutrition Australia iron fact sheet notes that haem iron is absorbed more efficiently than non-haem iron.

Useful animal based iron sources include:

• Lean red meat (beef, lamb, kangaroo)
• Chicken
• Fish including salmon and tinned tuna
• Eggs

Plant based iron options include:

• Kidney beans, chickpeas, green lentils
• Tofu
• Cashew nuts and almonds
• Rolled oats and wholemeal pasta
• Iron enriched breakfast cereals (such as Weetbix and All Bran) and wholegrain breads
• Spinach and broccoli
• Dried apricots

Absorption of non-haem iron improves when paired with foods high in vitamin C. A splash of lemon juice on lentils, a glass of orange juice with breakfast cereal, or capsicum in a salad can all help. The amount of iron absorbed from iron rich foods is reduced when tea, coffee, or foods high in calcium are eaten at the same meal. Spacing them out where possible is a simple everyday strategy.

For families with vegetarian or vegan teens, building meals around a wider mix of legumes, tofu, nuts and iron enriched grains, alongside vitamin C rich foods, helps support daily intake from a plant based diet.

What to know before considering iron supplements

Iron supplements are not a first step for teenage girls. The Victorian Department of Health's Better Health Channel advises against self-diagnosing iron deficiency, noting that although iron supplements are available without prescription, having too much iron in the body can be toxic. Taking an iron supplement when it isn't needed can also interfere with the body's absorption of other minerals, including zinc and copper.

Better Health Channel also explains that fatigue, paleness, dizziness and breathlessness are symptoms of many other health conditions, so iron supplements won't help the underlying issue if iron levels aren't the problem.

For teens without confirmed low iron, food first strategies are the sensible starting point. Adjusting meals to include more iron rich foods, pairing plant sources with vitamin C, and being mindful of meal time absorption blockers are all everyday steps that don't require professional oversight.

Why testing matters before supplementing

According to Better Health Channel, diagnosing iron deficiency involves a physical examination, medical history and blood tests arranged by a doctor. Diagnosis also aims to exclude other conditions that can cause similar symptoms.

Testing matters for a few reasons. Signs of low iron overlap with many other things, so a blood test provides objective information to work from. The results also guide what kind of support, if any, is helpful. And where iron levels are within normal range, testing can help rule iron deficiency in or out and points toward other things worth exploring if needed.

Starting iron supplements without testing can also mask other issues. If ongoing tiredness is being caused by something else, a supplement won't help and can delay finding the actual cause.

How to talk to a GP about tiredness and periods

Bringing up tiredness or period changes with a GP can feel awkward, especially for teens. A little preparation makes the conversation easier and more useful.

A few things worth doing before the appointment:

• Track periods for a couple of cycles. Note start and end dates, how heavy the flow feels, and any impact on daily activities. A period tracking app or a simple calendar note both work.
• List the signs and how long they've been going on. Include tiredness, energy levels, mood, concentration at school, and anything else that feels different.
• Note any diet changes or restrictions, such as vegetarian eating or reduced red meat.
• Bring a list of any medications or supplements the teen already takes.

For parents, respecting a teen's privacy during the appointment can help. Many GPs will offer some time to speak with the teen alone, which can make it easier to share what's really going on. If the conversation shifts toward practical dietary support, Dietitians Australia has a Find a Dietitian tool for locating an Accredited Practising Dietitian in your area, including those who offer telehealth.

Key takeaways for supporting teen energy and iron intake

Iron requirements go up sharply for girls once periods begin, with the RDI for females aged 14 to 18 sitting at 15 mg per day. Data from the ABS Usual Nutrient Intakes 2023 release shows that over one in three teen girls in Australia currently have iron intakes below the Estimated Average Requirement.

A varied diet including lean red meat, poultry, fish, legumes, tofu, nuts, iron enriched cereals and plenty of leafy greens forms the foundation of healthy iron intake. Pairing plant sources with vitamin C rich foods helps the body absorb non-haem iron.

Signs like ongoing tiredness, difficulty concentrating or heavier than usual periods are worth discussing with a GP rather than acting on alone. Iron supplements for teens should be considered only after a blood test and professional guidance. Small, consistent food choices, alongside open conversations about periods and energy, go a long way through this stage of life.

Frequently asked questions

Can periods affect iron levels in teen girls?

Yes. Menstruation involves regular blood loss, and blood carries iron. Iron requirements are higher for girls from age 14 partly for this reason, and iron losses can add up in those with heavier or longer periods.

How much iron do teenage girls need each day?

The RDI is 15 mg per day for girls aged 14 to 18, and 11 mg per day for boys the same age.

What foods are high in iron for teens?

Food including lean red meat, chicken, fish, kidney beans, lentils, chickpeas, tofu, cashew nuts, rolled oats, iron enriched breakfast cereals, spinach and dried apricots are high in iron for teens. Haem iron from animal foods is absorbed more efficiently than non-haem iron from plant foods.

What is the difference between low iron intake and iron deficiency?

Low iron intake is when the amount of iron eaten in a day falls short of the body's needs. Iron deficiency is typically diagnosed through an iron study blood test that a GP arranges alongside assessment of symptoms and medical history. Not everyone with low intake will develop iron deficiency, and not all iron deficiency shows obvious signs.

When should teens get their iron levels checked?

If ongoing tiredness, poor concentration, or heavier than usual periods are part of the picture, it's worth talking to a GP. A blood test can check iron stores and help work out what's going on.

Should teen girls take iron supplements?

Iron supplements for teens should only be considered after speaking with a GP. Both Healthdirect and Nutrition Australia note that iron in excess can be harmful, so testing and professional guidance come first.

Disclaimer: This article provides general information only and is not intended to diagnose, treat, cure, or prevent any disease. The information presented is not a substitute for professional medical advice. If you have concerns about your health, please consult your GP or healthcare provider for a personalised assessment and recommendations. Supplements should not replace a balanced diet.