What Are Micronutrients? Vitamins and Minerals Explained

Food labels, health articles and supplement adverts all throw around words like vitamins, minerals and micronutrients, usually without stopping to say what they mean. Once you've got the basic idea, a lot of the confusion about eating well falls away.

Here's how I'd explain it, based on the World Health Organization and the NHS pages on vitamins and minerals. It's general education, not personal advice. If you're worried about a deficiency or thinking about supplements, a GP or registered dietitian is the right person to ask.

What micronutrients are, in plain English

The World Health Organization defines micronutrients as vitamins and minerals needed by the body in very small amounts. The NHS puts it in similar terms: vitamins and minerals are nutrients your body needs in small amounts to work and stay healthy.

The "micro" part is about quantity, not importance. You need only tiny amounts compared with the larger quantities of carbohydrate, protein and fat, but missing out on them can still cause real problems.

The main vitamins and minerals your body needs

The NHS vitamins and minerals guide covers a long list. The vitamins include A, the B vitamins and folic acid, C, D, E and K. The minerals include calcium, iodine and iron, plus others such as copper, potassium and zinc. You don't need to memorise them. It helps more to know that each one has its own jobs, and no single food provides all of them.

What a few key micronutrients do and where they come from

The NHS has a page for each nutrient. Here are three to show how different they are:

Micronutrient	What the NHS says it does	Some food sources
Iron	Helps make red blood cells, which carry oxygen around the body	Red meat, beans and pulses, nuts, dried apricots, fortified breakfast cereals
Calcium	Helps build strong bones and teeth, controls muscle movement and helps blood clot	Dairy products, calcium-enriched soya drinks, fortified bread and flour, sardines eaten with their bones
Vitamin C	Helps protect cells, supports skin, blood vessels and bones, and helps wounds heal	Citrus fruit, peppers, strawberries, blackcurrants, broccoli

Vitamin D is slightly different because your body can make it. The NHS says that from about late March or early April to the end of September most people can make enough from sunlight on their skin, but from October to early March the sunlight isn't strong enough. Food sources include oily fish, red meat, egg yolks and fortified foods.

Can you get micronutrients from food alone?

For most people, yes. The NHS says most people should get all the nutrients they need from a varied and balanced diet. The pages for iron, calcium and vitamin C all repeat the same message, so you don't usually need to count milligrams.

Variety is the useful bit. Different foods carry different nutrients, so a plate with beans, vegetables, fruit, dairy or alternatives and wholegrains tends to cover more ground than a repetitive diet. If you're curious about the bigger nutrients that sit alongside them, I've also written about what macronutrients are. Another useful idea is the glycemic index, which looks at how quickly carbohydrate foods raise blood glucose.

When micronutrient supplements may be suggested

Some groups are advised to think about supplements. The NHS says everyone should consider a daily 10 microgram vitamin D supplement in autumn and winter, and recommends one all year round for people who rarely go outdoors, people who usually cover most of their skin outside, people with dark skin, and all children aged 1 to 4. Women with heavy periods are at higher risk of iron deficiency and may need iron supplements, according to the NHS.

The key point is that these are specific groups with specific advice. It isn't a case of taking everything just in case.

Why more isn't always better with vitamins and minerals

Taking too much of a nutrient can cause problems. The NHS pages give examples:

• Iron doses over 20 milligrams can cause constipation, nausea, vomiting or stomach pain, and very high doses can be fatal, especially for children. Keep supplements out of their reach.
• Vitamin C above 1,000 milligrams a day can cause stomach pain, diarrhoea and wind.
• Calcium above 1,500 milligrams a day can cause stomach pain and diarrhoea.
• Taking too much vitamin D over time can raise calcium levels in the body to harmful levels.

If a doctor has prescribed a particular dose, follow that advice. Otherwise, check the label and ask a pharmacist, GP or dietitian before starting anything, especially if you're pregnant, taking medicines or living with a health condition.

Why deficiencies matter worldwide

The WHO says iron, vitamin A and iodine deficiencies are the most common worldwide, especially in children and pregnant women. It notes that severe iodine deficiency can cause brain damage, and that vitamin A deficiency is a leading cause of preventable childhood blindness. WHO's approach includes diverse healthy diets, fortifying foods and supplements where needed, and salt iodisation is its preferred strategy for iodine.

Sharing what you know about nutrition

If you're a registered nutrition professional who can explain vitamins and minerals clearly, readers are looking for exactly that.

Qualified nutrition writers can browse food and nutrition sites that welcome expert articles.

Frequently asked questions

Are micronutrients the same as vitamins?

Vitamins are one half of the picture. The WHO describes micronutrients as vitamins and minerals, so minerals such as iron, calcium and iodine count too.

Why are they called micronutrients?

Because the body needs them in very small amounts, compared with the larger amounts of carbohydrate, protein and fat.

Can I get enough from a balanced diet?

The NHS says most people should get all the nutrients they need from a varied and balanced diet. Some groups are advised to take specific supplements.

Can you take too many vitamins or minerals?

Yes. NHS pages list problems from too much iron, vitamin C, calcium and vitamin D, which is why it's worth checking labels and asking a pharmacist or GP.

Which deficiencies does the WHO say are most common?

The WHO says iron, vitamin A and iodine deficiencies are the most common worldwide, especially among children and pregnant women.