Struggling with exams? Low iron levels might be the hidden culprit

With exams coming up, many South African students are busy with past papers and late-night study sessions.

But there’s another factor that can quietly get in the way of revision: low iron levels and anaemia, which are often overlooked.

Research shows these issues don’t just affect your health; they can impact memory, focus, mood, and how well your brain handles stress. If you or someone you know is studying hard, paying attention to iron levels can really help, and there are steps you can take.

Anaemia refers to a condition where there aren’t enough healthy red blood cells (or enough haemoglobin) in the blood, which means less oxygen gets to your brain and muscles. Low iron stores, even before full anaemia develops, can have similar effects.

For adolescents, whose bodies and brains are still developing, this is especially important. In South Africa, studies show that many teenagers have an iron deficiency or low iron levels, even if they’re not officially anaemic.

For example, a study of adolescents in Cape Town’s psychiatric inpatient unit found that about 22.6% had iron deficiency, and 7.6% were already anaemic.

When iron levels are low, students may feel constantly fatigued, find it harder to concentrate, and experience what many describe as ‘mental fog, says Sister Karin Davidson of the Cape Town Infusion Centre.

“These symptoms often peak during exam time, making an already stressful period even harder to manage.”

Female students were especially vulnerable due to several factors, such as menstruation, which causes iron loss, growth spurts, which increase nutritional demands, and dietary habits that may not provide enough iron.

Around the world, anaemia in children and teenagers can cause problems with attention, slower thinking, weaker memory and mood changes. These challenges can make it much harder to study and perform well during exams.

According to the World Health Organisation (WHO), over 103 million children in Africa are affected by anaemia. A 2021 study in "The Lancet" estimated that one in four people globally may be experiencing anaemia during their most critical learning years.

Exams are already tough on both mind and body.

Low iron can make many common student challenges even harder to manage:

• Brain fog and poor concentration: Without enough iron, the brain struggles to maintain alertness and filter distractions. Studies show that adolescents with iron deficiency anaemia score more poorly on attention/concentration tasks.
• Memory retention suffers: Whether learning new facts, recalling formulas, or writing essays, memory is central. Iron supplementation has been shown to improve working memory, intelligence measures, and memory in school-age children with low iron/anaemia.
• Mood, fatigue, and stress response: If you feel tired, irritable, anxious, or overwhelmed, it might not just be stress. Low haemoglobin or iron can drain your energy and make stress feel even worse.

Sleep and study disruption

Poor iron status can lead to sleep problems (night waking, restless sleep) and daytime tiredness. When students try to catch up with late-night studying, that worsens both sleep and iron absorption.

Girls are at higher risk (growth spurts, menstruation, etc.). Socioeconomic factors, diet quality, food access, and awareness play big roles.

Kath Megaw, registered dietitian and founder of Nutripaeds, stresses the importance of nutritional support during exams. “Having a stress-responsive nutrition strategy is as crucial to preparing for exams as revision.”

Dietitian-approved strategies for this exam season:

Check your iron status. Start by speaking with a parent or guardian about your concerns. You can also ask a school nurse or visit a local clinic to request a blood test.

They will typically check your haemoglobin and ferritin levels. If ferritin is low, you may have “latent iron deficiency” even if you're not yet anaemic. Early detection means you can act before exam performance takes a hit.

Nutrition tweaks

• Eat iron-rich foods: lean red meat, chicken, fish, legumes, spinach, beans, and fortified cereals. For affordable local options, consider incorporating tinned pilchards, beans, or maize meal into your diet.
• Pair with vitamin C: oranges, peppers, and berries help your body absorb iron.
• Avoid inhibitors around meals: coffee, tea, and calcium-rich dairy near your iron meal can reduce absorption.
• Include foods that support mood and energy: healthy fats, protein, and whole grains.
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Smart study rhythms

• Don’t skip regular meals. Hunger and low blood sugar make focus hard.
• Work out when you study best (morning vs night) and arrange your “heavy thinking” time for when your brain is most refreshed.
• Prioritise sleep: it helps consolidate memory and repair the body; iron status is tied to sleep quality.

Supplementation and medical support

If diet alone isn't sufficient or tests confirm deficiency or anaemia, talk to a healthcare provider about iron supplements. Over-the-counter options are available, but it is crucial not to self-medicate due to the risks of overdose, possible side effects, or interactions. Medical advice is essential to ensure safe and effective treatment.

Stress management matters

Managing anxiety, taking breaks, exercising (even walking), and staying hydrated all help reduce the extra cognitive load that low iron makes more burdensome. Because exam seasons tend to exacerbate existing vulnerabilities.

Low iron isn’t something that always “suddenly” hits; it builds over time. If you enter exams already running on low iron, you’re starting at a disadvantage. Even small gains (better iron status, better sleep, stable routine) can improve recall, reduce anxiety, and give you more consistent performance.​