Low iron is common in teenage girls – with vegans and vegetarians at greatest risk, according to our research in Sweden
Teenage girls who avoid meat in favour of a plant-based diet are at higher risk of developing an iron deficiency, according to our latest research.
Our study confirmed that iron deficiency is common among teenage girls, with 38% of participants affected. We also found that risk of iron deficiency was strongly associated with both eating patterns and menstrual blood loss. Girls who reported heavy periods and followed a meat-restricted diet – meaning they were vegetarian, vegan, pescatarian or avoided red meat – had by far the highest risk of developing iron deficiency. We found that nearly 70% of vegans and vegetarians had iron deficiency.
As a growing number of young people turn to sustainable eating practices, this condition could become even more common. This is why it’s important teenagers are properly informed about the risks of low iron – and how they can get enough iron even while following a plant-based diet.
The idea for this study came from the personal experience of one of us, whose teenage daughter struggled with fatigue, low mood and poor stamina. After months of assuming it was stress or excess screen time, blood tests revealed the cause: iron deficiency anaemia. The experience made us wonder whether the issue is more widespread. This sparked a research collaboration that brought together clinical and nutritional expertise.
The study included 475 female high school students from southern Sweden. Participants completed questionnaires about their diet, what supplements they used, as well as their menstrual patterns. They also provided blood samples, which were analysed for haemoglobin and ferritin – the key markers used to assess iron status.
The body contains about as much iron as a two-inch nail. Around two-thirds of the body’s iron is used in red blood cells to carry oxygen from the lungs to the rest of body. This is why a deficiency can cause tiredness, pale skin and shortness of breath.
But iron isn’t just about oxygen. The remaining one-third plays a key role in brain function, energy metabolism and nerve signalling. Studies show that even without anaemia, low iron can lead to fatigue, poor concentration, reduced academic performance and physical tiredness. Treating iron deficiency has been linked to reduced fatigue.
Teenage girls are at particular risk of iron deficiency. There are several reasons for this.
First, the body needs extra iron to keep up with the rapid growth that happens during puberty. Second, menstruation leads to iron loss, with periods often heavy during the first years after menarche (a woman’s first period). Third, diet plays a key role. Many girls also change their eating habits during adolescence, often reducing their intake of red meat or animal products. But even among omnivores, iron intake tends to be too low. It’s not just about what they avoid – it’s that many simply aren’t getting enough iron overall.
While our findings are from Sweden, the issue is not unique to the country. A European school-based study from 2006-2007 found iron deficiency in 26% of girls aged between 12 and 17. Data from the United States also found that around 17% of girls aged 12 to 21 have low iron stores. Study methods may differ, but the trend is consistent: adolescent girls across countries are at risk of iron deficiency – often without knowing it.
Despite how common iron deficiency is, several persistent myths can prevent young people from getting the help they need.
One common belief is that eliminating animal products is inherently healthy, without acknowledging the need to replace the nutrients they supply.
A plant-based diet can absolutely be healthy and sustainable. But when animal sources of iron are removed, it’s essential to include iron-rich plant foods and to combine them with certain foods for better absorption. Without that knowledge, even well-intentioned choices can lead to nutritional gaps.
Another common belief is that low iron would be obvious – that you’d feel if you had it.
In reality, iron deficiency and anaemia often develops slowly and the body adapts over time. Symptoms such as tiredness, poor concentration and low mood can sneak up gradually and become the new normal.
A third misconception is that iron supplements are dangerous or unnecessary.
For those diagnosed with a deficiency, supplements are often essential and safe when used properly. Treatment usually needs to continue for at least three months to restore the body’s iron stores.
Iron intake
So, what can be done? Here are three simple, evidence-based tips for a sustainable iron-rich diet:
Make iron part of your daily routine. Whole grains, legumes and leafy greens (such as spinach, kale and chard) are good plant-based sources of iron. Even in a balanced diet, where a person consumes a maximum of 500g of red meat per week, more than 80% of daily iron intake comes from plant-based sources.
Help your body absorb it. Plant-based iron is often tightly bound to phytic acid and needs help to be released. So it’s important to combine iron-rich meals with enhancers such as vitamin C (citrus fruits, peppers and cruciferous vegetables) or natural acids (citrus juice, vinegar, soy sauce, miso, kimchi or sauerkraut). These enhancers help improve iron absorption. You can also use fermentation to your advantage. Foods such as sourdough bread have gone through processes that reduce phytic acid, making iron more accessible.
Avoid iron blockers. Skip tea or coffee with meals. The tannins they contain can significantly reduce iron absorption.
With the right knowledge, young people can eat both sustainably and healthily – and avoid iron deficiency and its consequences.
Moa Wolff receives funding from the Southern Health Care Region of Sweden, the Lions Research Fund Skåne, and Regional Funding for Clinical Research (USVE). She has also received an honorarium from Pharmacosmos for giving an educational webinar.
Anna Stubbendorff does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.