Minerals are micronutrients needed by the body in small amounts, but they have important roles in health. For AQA GCSE Food Preparation and Nutrition, you need to understand the functions, sources and possible effects of too little or too much calcium, iron and sodium. This guide explains the key facts in an exam-ready way and links them to foods you may use in practical work. Remember that dietary guidance can change, so check the current AQA specification and relevant official health guidance when revising.
What are minerals?
Minerals are inorganic nutrients. This means they do not come from living substances in the same way as carbohydrate, protein and fat, and they do not provide energy. They are micronutrients because the body needs them in relatively small amounts. Small amounts does not mean they are unimportant: minerals support body processes such as building bones, carrying oxygen and controlling fluid balance.
The amount a person needs can vary according to factors including age, sex and life stage. A balanced diet usually provides the minerals needed by most healthy people. However, a diet that lacks variety, or regularly contains too much salt, can affect health.
Calcium
Calcium is best known for helping to build and maintain strong bones and teeth. It also contributes to normal muscle contraction and blood clotting. During childhood and the teenage years, having enough calcium is particularly important because bones are still developing.
Sources of calcium
- Milk, yoghurt and cheese
- Fortified plant-based drinks, where calcium has been added
- Some green leafy vegetables
- Fish with edible bones, such as canned sardines
- Tofu and some fortified foods
When planning a meal, a yoghurt-based dressing, cheese in a vegetable dish or a calcium-fortified ingredient can help increase calcium content. Check the label of a plant-based drink because not every product has the same nutritional profile.
Too little calcium
A long-term lack of calcium can contribute to weak bones. In children, severe deficiency can be linked with rickets, a condition in which bones become soft and may develop abnormally. In later life, low bone density can increase the risk of osteoporosis. Calcium works alongside other nutrients, including vitamin D, which helps the body absorb calcium, so nutrients should not be considered in isolation.
Iron
Iron is needed to make haemoglobin. Haemoglobin is the protein in red blood cells that carries oxygen around the body. Iron also supports the release of energy from food and normal immune function.
Sources of iron
- Red meat, including beef and lamb
- Liver, although it should not be eaten frequently by some groups because it contains high levels of vitamin A
- Pulses such as lentils, chickpeas and beans
- Green leafy vegetables
- Fortified breakfast cereals and bread
- Nuts and seeds
Iron from animal foods is called haem iron. Iron from plant foods is called non-haem iron. Including a source of vitamin C, such as peppers, tomatoes or fruit, with a meal containing plant sources of iron can help the body absorb non-haem iron. Tea and coffee can reduce iron absorption when consumed with meals, so meal timing can be relevant when discussing iron intake.
Too little iron
Iron deficiency can lead to iron-deficiency anaemia. Anaemia means the blood cannot carry oxygen as effectively as it should. Possible effects include tiredness, weakness and reduced concentration. These symptoms can have other causes, so they are not a diagnosis. In an exam answer, link the mineral to its function: too little iron means less haemoglobin can be made, reducing oxygen transport.
Sodium
Sodium helps control the balance of fluids in the body. It is also involved in nerve impulses and muscle contraction. Most sodium in the diet comes from salt, which is sodium chloride, or from foods containing added salt.
Sources of sodium
- Table salt added during cooking or at the table
- Processed meats, such as bacon and sausages
- Cheese
- Bread and savoury snacks
- Stock cubes, sauces and ready meals
Some foods may not taste very salty but can still contribute significant sodium. Reading nutrition labels and comparing products can help when adapting a recipe. For example, use herbs, spices, garlic, citrus juice or other flavourings to reduce reliance on added salt. Do not assume that every product labelled as healthy has the same sodium content.
Too much sodium
Eating too much sodium over time can contribute to high blood pressure in some people. High blood pressure increases the risk of cardiovascular disease and stroke. This is why current healthy-eating guidance generally recommends limiting salt and checking processed foods. Exact advice and labelling guidance can change, so use the latest information from the NHS, Food Standards Agency or GOV.UK rather than relying on an old figure.
Comparing the three minerals
| Mineral | Main function | Useful food sources | Key issue if intake is unsuitable |
|---|---|---|---|
| Calcium | Strong bones and teeth; muscle contraction; blood clotting | Dairy foods, fortified products, green vegetables, fish with edible bones | Low intake can contribute to weak bones; too much sodium is a separate concern |
| Iron | Making haemoglobin to transport oxygen | Meat, liver, pulses, green vegetables, fortified cereals | Low intake can cause iron-deficiency anaemia |
| Sodium | Fluid balance, nerve impulses and muscle contraction | Salt and many processed foods | Too much can contribute to high blood pressure |
Applying mineral knowledge in practical work
Mineral knowledge can inform recipe development without becoming a list of isolated facts. If you are developing a vegetarian dish, combine pulses or fortified cereal products with vegetables or fruit containing vitamin C when discussing iron. If a recipe contains cheese, yoghurt or fortified ingredients, identify its possible calcium contribution. If a dish uses stock cubes, processed meat or a salty sauce, consider how the sodium content could be reduced while keeping the food appealing.
Use accurate language. A food can be a source of a mineral, but one ingredient does not automatically make a whole meal nutritionally balanced. Consider portion size, the rest of the meal and the needs of the intended customer or consumer.
Exam-ready retrieval checklist
- Can you explain why minerals are called micronutrients?
- Can you give two functions of calcium?
- Can you name several calcium-rich foods?
- Can you define haemoglobin and link it to iron?
- Can you distinguish haem iron from non-haem iron?
- Can you explain what iron-deficiency anaemia means?
- Can you state three roles of sodium?
- Can you identify common sources of hidden sodium in processed foods?
- Can you suggest a practical way to improve a recipe’s mineral profile?
- Can you explain the difference between a food source and a health claim?
For the precise content required, use the AQA GCSE Food Preparation and Nutrition specification. Check current NHS, Food Standards Agency and GOV.UK guidance for advice that may be updated.