Áine's Iron: A Vegetarian Teenager with Low Ferritin
Áine is 15 and has been vegetarian since she was 12. She attends the GP complaining of tiredness, breathlessness on stairs and dizziness when standing. She is pale, her fingernails are spoon-shaped, and her periods are heavy and last seven days. Blood results: haemoglobin 10.2 g/dL (reference 12–16) and ferritin 8 µg/L (reference 15–150). She has been prescribed oral iron. A typical school day looks like this: no breakfast; a white bread sandwich with cheese at 11:00; a bag of crisps and a diet cola at 15:00; pasta with cheese sauce at 18:00; and a mug of tea with both meals. She eats no beans, lentils, nuts, seeds or dark green vegetables and says she hates them. She drinks 500 ml of milk a day and takes a calcium supplement because her mother read that teenagers need it.
1. Using the data given, explain the dietary and non-dietary factors most likely contributing to Áine's low iron status.
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Haemoglobin 10.2 g/dL with ferritin 8 µg/L shows iron-deficiency anaemia with depleted stores - not simply tiredness. Three things are happening at once.
Supply: her diet contains almost no iron-dense food. As a vegetarian she depends on non-haem iron from lentils, beans, tofu, nuts, seeds, dark green vegetables and fortified cereals, and she eats none of these. White bread, pasta, cheese, crisps and cola are very low in iron, and skipping breakfast removes a whole meal's worth.
Absorption: non-haem iron is poorly absorbed, roughly 1–10 %, and is inhibited by the calcium in the cheese and the 500 ml of milk and by the tannins in the tea she drinks with both meals. She has no vitamin-C source at any meal, so nothing is enhancing absorption either.
Loss: seven-day heavy periods mean a large, recurring iron loss that her intake cannot replace, which is why stores fell first. If the calcium supplement is taken with meals, it adds a further inhibitor.
The judgement is that this is not just 'eat more iron' - intake, absorption and loss all need to be addressed, and the heavy periods need medical follow-up.
2. Plan a realistic one-day menu that would improve her iron intake and absorption while remaining vegetarian and acceptable to her. Justify two specific changes you have made.
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Breakfast: fortified wholegrain cereal or porridge with fortified plant milk, plus a small glass of orange juice. Mid-morning: wholemeal pitta with hummus. Lunch: lentil and vegetable soup with wholemeal bread, followed by a kiwi. Afternoon: a handful of almonds and some dried apricots instead of crisps and cola. Dinner: chickpea, spinach and tomato curry with rice; water with lemon, no tea. Supper: toast with peanut butter.
Two changes worth justifying:
- Add legumes and fortified cereal at every meal. These are her most realistic non-haem iron sources and spread intake across the day rather than one hit; fortified cereal is useful because the iron added is often well absorbed.
- Pair a vitamin-C source with each iron meal. Vitamin C at the same meal can multiply non-haem iron absorption several-fold by keeping iron in its more absorbable form. Moving tea and the calcium supplement to between meals removes the two main inhibitors.
Portions must stay realistic - a plan she will not eat is worthless. The prescribed iron will do most of the repair; the diet keeps it repaired, so the menu must be sustainable, not perfect.
3. Explain why the timing of her tea, milk and calcium supplement matters, and state the advice you would give her.
Read the worked answer
Tea contains tannins (polyphenols) and milk contains calcium; both bind non-haem iron in the gut and reduce how much is absorbed, and the effect is strongest when they are consumed with the meal. Áine drinks tea with both meals and has cheese or milk at both, so her already low iron intake is being absorbed at close to the worst possible rate. The calcium supplement adds a further dose of the same inhibitor.
Advice:
- Take the prescribed iron tablet with orange juice or another vitamin-C source, ideally on an empty stomach or with a light snack, unless the GP advises otherwise because of stomach upset.
- Leave at least one to two hours between the tablet and tea, coffee, milk or the calcium supplement.
- Take the calcium supplement at bedtime, well away from iron-containing meals.
- Drink tea between meals rather than with them, and keep milk as a drink at times when little iron is being eaten.
- Do not stop the tablets when she feels better: refilling stores takes months.
- Ask the GP about investigating the heavy periods, because diet alone cannot offset a large monthly blood loss.