What is a mineral?

You’ve heard of calcium and magnesium but how much do you know about what they – and other minerals – do? Get the lowdown with our minerals masterpiece

By Madeleine Bailey on January 26, 2019 Reviewed by Dr Sarah Schenker on January 30, 2019

We’ve all heard of the ‘big name’ minerals; calcium, magnesium and zinc. But how many of us understand they role they play in our health and wellbeing? And what about the ‘best-supporting’ minerals, too? It’s time to open your mind to minerals.

What are minerals?

Unlike vitamins, which come from living sources such as plants and animals, minerals are inorganic substances derived from rocks, soil or water. They are essential in our diet because they cannot be made in the body. They have many functions and are needed for healthy bones, muscles, blood, tissues and organs, plus they keep our nervous and immune systems working efficiently.¹

What types of minerals are there?

Minerals are divided into two groups, major and minor – also known as trace elements.² Major minerals are those we need 100mg or more of every day. They include calcium, magnesium, phosphorus, potassium, sodium and chloride. We need less of the trace minerals – chromium, copper, iodine, iron, fluoride, manganese, selenium and zinc – but that doesn’t mean they are less important. Iron, for example, is vital for healthy blood cells that carry oxygen around the body.³

What key minerals do we need?

All the minerals have essential roles but some are more important for certain groups of people. For instance, girls and women under 50 need significantly more iron than men and post-menopausal women – 14.8mg per day compared with 8.7mg – to offset the iron lost during periods and pregnancy.⁴ Calcium and magnesium, vital for bones, are important for teens because we build up 90% of our bone mass by the ages of 18 to 20.⁵ After 35, we begin to lose bone density, so these minerals also matter from midlife. After 50, 50% of women and 20% of men will have a fracture due to bone loss, which may be linked to poor mineral intake.⁶ Magnesium is also key for healthy nerve, muscle and psychological function, and helps regulate potassium and sodium too, which are involved in controlling blood pressure.⁷ Zinc and selenium both play a role in immunity, as well as fertility and reproduction – especially in men.⁸ Along with iodine, selenium supports the thyroid gland to work efficiently, while copper has a long list of jobs, from helping the body use iron to brain development, maintaining immune function and much (much!) more.⁹

What are the best sources of minerals?

The best food sources of minerals include:^10-13

• calcium – dairy products, broccoli, cabbage, okra, tofu, soya beans, nuts, and fish where you eat the small bones, such as sardines
• magnesium – dairy foods, spinach, nuts, meat, fish, brown rice and wholegrain bread
• potassium – bananas, broccoli, pulses, nuts and seeds, meat and fish
• zinc – meat, shellfish, dairy products, bread whole grain cereals
• selenium – Brazil nuts, meat, fish, eggs
• iodine – sea fish, shellfish and some grains, depending on the soil
• copper – liver, kidney, nuts and wholegrain cereals

• iron – meat, beans, nuts, dried fruit, wholegrains and green leafy vegetables

As with all nutrients, minerals are absorbed more efficiently from food than from supplements. But how easily they are absorbed depends on their source and what you eat them with. For example, we can absorb 20-40% of the iron found in meat compared with 5-20% from plant sources.¹⁴ However, vitamin C converts it to a more bioavailable chemical form, increasing its absorbability.¹⁵ You may need supplements if you have:¹⁶

• a diagnosed mineral deficiency
• a restricted diet such as veganism
• food intolerances
• been prescribed certain medications
• a condition that stops you absorbing nutrients, such as Crohn’s or coeliac disease

A well-balanced diet should provide enough minerals for most people, but a multi-nutrient supplement can provide a reassuring top-up if necessary.

What happens if we don’t get enough of certain minerals?

The biggest issue here is iron deficiency anaemia; it’s actually the world’s most common nutritional deficiency, with vegans, some vegetarians, girls and women under 50 are most at risk. You may feel very tired, look pale, have palpitations and feel breathless. Some people also experience headaches, hair loss or mouth ulcers.¹⁷ Mineral deficiency symptoms are wide-ranging but you may feel tired, become more susceptible to infections, have aches and pains, and may have a poor appetite or digestive problems.¹⁸ In the UK, low intakes of certain minerals are more common than an outright deficiency. Our National Diet and Nutrition Surveys show that men tend to have low intakes of potassium, magnesium and zinc, while women aren’t getting enough iron, calcium, copper and iodine.¹⁹

What happens if we consume too much of one mineral?

We’re most at risk of too much sodium, found in salt, which can lead to high blood pressure, heart disease, kidney disease and more.²⁰ Research shows we’re consuming around 8.6g of salt per day – that’s over 2g more than the recommended limit of 6g (around a teaspoon).²¹ One of the problems is that 75% of our salt intake comes from processed food, including cheese, bread and breakfast cereals.²² Many manufacturers only put sodium on the packaging, but you can convert sodium to salt by multiplying it by 2.5 i.e.1g of sodium becomes 2.5g of salt.²³ Consuming too much of one mineral can put others out of balance. For example, too much iron may block your absorption of zinc.²⁴ That’s why taking one mineral in isolation isn’t a good idea unless your doctor or other healthcare professional has recommended you do so. Shop Minerals Advice is for information only and should not replace medical care. Please check with your GP before trying any remedies. Sources 1. British Nutrition Foundation. What are minerals? 2. Netdoctor. Sources of minerals 3. As above 4. NHS. Iron 5. British Nutrition Foundation. Women 6. As above 7. As Source 2 8. British Nutrition Foundation. Zinc 9. EU Register of Nutrition and Health Claims Made on Foods. Iron. Selenium. Copper 10. NHS. Calcium 11. NHS. Others: Vitamins and minerals 12. NHS. Iodine 13. British Nutrition Foundation. Copper 14. As Source 2 15. As Source 2 16. Healthline. Mineral deficiency 17. NHS. Iron deficiency anaemia 18. As Source 16 19. As Source 1 20. Blood Pressure UK. Salt’s effects on your body 21. World Action on Salt and Health. UK 22. As above 23. NHS. Salt: the facts 24. As Source 1