As well as vitamins and more common minerals, a healthy diet includes many other nutrients.
This section has information on:
Beta-carotene
Beta-carotene gives yellow and orange fruit and vegetables their colour. It's turned into vitamin A in the body, so it can do the same jobs in the body as vitamin A.
Good sources of beta-carotene
The main sources of beta-carotene are:
- green (leafy) and yellow or red vegetables – such as spinach, carrots and red peppers
- yellow fruit – such as mango, papaya and apricots
How much beta-carotene you need
You should be able to get the amount of beta-carotene you need by eating a varied and balanced diet.
If you decide to take beta-carotene supplements, do not take too much as this could be harmful.
Do not take more than 7mg of beta-carotene supplements a day unless advised to by your GP.
Effects of taking too much beta-carotene
There's no evidence that the beta-carotene we get from food is harmful.
But beta-carotene supplements could increase the risk of lung cancer in people who smoke or have been heavily exposed to asbestos.
If you smoke or have been exposed to asbestos, you should not take beta-carotene supplements.
Chromium
You should be able to get all the chromium you need by eating a varied and balanced diet.
Good sources of chromium include:
- meat
- nuts
- cereal grains
If you take chromium supplements, do not take too much as this might be harmful. Having 10mg or less a day of chromium from food and supplements is unlikely to cause any harm.
How much chromium you need
Around 25 micrograms of chromium a day should be enough for adults. A microgram is 1,000 times smaller than a milligram (mg).
The word microgram is sometimes written with the Greek symbol μ followed by the letter g (μg).n
Copper
Copper helps:
- produce red and white blood cells
- trigger the release of iron to form haemoglobin, the substance that carries oxygen around the body
It's also thought to be important for:
- infant growth
- brain development
- the immune system
- strong bones
If you take copper supplements, do not take too much as this could be harmful. Having 10mg or less a day of copper supplements is unlikely to cause any harm.
Good sources of copper
Good sources of copper include:
- nuts
- shellfish
- offal
How much copper you need
Adults aged 19 to 64 need 1.2mg of copper a day.
You should be able to get all the copper you need from your daily diet.
Effects of taking too much copper
Taking high doses of copper could cause:
- stomach pain
- sickness
- diarrhoea
- damage to the liver and kidneys (if taken for a long time)
Magnesium
Magnesium is a mineral that helps:
- turn the food we eat into energy
- make sure the parathyroid glands work normally - these produce hormones that are important for bone health
You should be able to get all the magnesium you need by eating a varied and balanced diet.
If you take magnesium supplements, do not take too much as this could be harmful. Having 400mg or less a day of magnesium from supplements is unlikely to cause any harm.
Good sources of magnesium
Magnesium is found in a wide variety of foods, including:
- spinach
- nuts
- wholemeal bread
How much magnesium you need
The amount of magnesium adults aged 19 to 64 need is:
- 300mg a day for men
- 270mg a day for women
Effects of taking too much magnesium
Taking high doses of magnesium (more than 400mg) for a short time can cause diarrhoea.
There's not enough evidence to know the possible effects of taking high doses of magnesium for a long time.
Manganese
Manganese helps make and activate some of the enzymes in the body. Enzymes are proteins that help the body carry out chemical reactions, such as breaking down food.
Good sources of manganese
Manganese is found in a variety of foods, including:
- bread
- nuts
- breakfast cereals (especially wholegrain)
- green vegetables – such as peas
How much manganese you need
You should be able to get all the manganese you need from your daily diet.
If you take manganese supplements, do not take too much as this could be harmful.
For most people, taking 4mg or less of manganese supplements a day is unlikely to cause any harm.
Older people may be more sensitive to manganese. But taking 0.5mg or less of manganese supplements a day is unlikely to cause any harm.
Effects of taking too much manganese
Taking high doses of manganese for a long time might cause muscle pain and nerve damage. It could also cause other symptoms, such as fatigue and depression.
Molybdenum
Molybdenum helps make and activate some of the enzymes in the body that help with repairing and making genetic material. Enzymes are proteins that help the body carry out chemical reactions.
You should be able to get all the molybdenum you need by eating a varied and balanced diet.
Good sources of molybdenum
Molybdenum is found in a wide variety of foods. Foods that grow above the ground are usually higher in molybdenum than foods that grow below the ground, such as potatoes or carrots.
The molybdenum we get from food is not likely to be harmful.
How much molybdenum you need
You should be able to get all the molybdenum you need from your daily diet.
Effects of taking too much molybdenum
There's some evidence to suggest taking molybdenum supplements might cause joint pain.
Phosphorus
Phosphorus is a mineral that helps build strong bones and teeth and helps release energy from food.
Good sources of phosphorus
Phosphorus is found in many foods.
Good sources include:
- red meat
- dairy foods
- fish
- poultry
- bread
- brown rice
- oats
How much phosphorus you need
Adults need 550mg of phosphorus a day.
You should be able to get all the phosphorus you need from your daily diet.
If you take phosphorus supplements, it's important not to take too much as this could be harmful.
Taking 250mg or less a day of phosphorus supplements on top of the phosphorous you get from your diet is unlikely to cause any harm.
Effects of taking too much phosphorus
Taking high doses of phosphorus supplements for a short time can cause diarrhoea or stomach pain.
Taking high doses for a long time can reduce the amount of calcium in the body. This means bones are more likely to fracture.
Potassium
Potassium is a mineral that helps control the balance of fluids in the body. It also helps the heart muscle work properly.
Good sources of potassium
Potassium is found in most types of food.
Good sources of potassium include:
- bananas
- some vegetables – such as broccoli, parsnips and brussels sprouts
- beans and pulses
- nuts and seeds
- fish
- beef
- chicken
- turkey
How much potassium you need
Adults aged 19 to 64 need 3,500mg of potassium a day. You should be able to get all the potassium you need from your daily diet.
Effects of taking too much potassium
Taking too much potassium can cause stomach pain, feeling sick and diarrhoea.
If you take potassium supplements, do not take too much as this could be harmful.
Taking 3,700mg or less of potassium supplements a day is unlikely to have obvious harmful effects.
But older people may be more at risk of harm from potassium. This is because their kidneys may be less able to remove potassium from the blood.
Older people should not take potassium supplements unless advised to by their GP.
Selenium
Selenium helps the immune system work properly. It also helps prevent damage to cells and tissues.
Good sources of selenium include:
- brazil nuts
- fish
- meat
- eggs
If you take selenium supplements, it's important not to take too much as this could be harmful. Taking 350μg or less a day of selenium supplements is unlikely to cause any harm.
How much selenium you need
The amount of selenium adults aged 19 to 64 need is:
- 75μg a day for men
- 60μg a day for women
If you eat meat, fish or nuts, you should be able to get all the selenium you need from your daily diet.
Effects of taking too much selenium
Too much selenium causes selenosis. The mildest form of this condition can cause a loss of hair and nails.
Sodium chloride (salt)
Sodium chloride is commonly known as salt.
Your body needs sodium and chloride minerals in small amounts to help keep the level of fluids in the body balanced. Chloride also helps the body digest food.
Adults should eat no more than 6g of salt a day (about 1 teaspoon). On average, we eat 2.1g more salt than we should each day.
You should try to cut down on salt. Sodium chloride should not be used in supplements.
Sources of salt
Salt is found naturally at low levels in all foods.
But some salt is added to many processed foods, such as:
- ready meals
- meat products – such as bacon
- some breakfast cereals
- cheese
- tinned vegetables with added salt
- some bread
- savoury snacks
How much salt you need
You should have no more than 6g of salt (2.4g of sodium) a day.
But people in Ireland eat about 10g of salt (about 4g of sodium) a day. This is much more than the body needs.
Tips for cutting down on salt:
- Check food labels and choose foods with less salt – for products with colour-coded labels, try to pick food with more greens and ambers, and fewer reds.
- Choose tinned vegetables and pulses with no added salt.
- Choose tinned fish in spring water rather than brine.
- Use sauces like soy sauce, brown sauce, ketchup and mayonnaise sparingly - these are often high in salt.
- Eat fewer salty snacks and foods, such as crisps, salted nuts, bacon, cheese, pickles and smoked fish.
- Add less or no salt when cooking, use herbs and spices for flavour instead.
- Choose low-salt stock cubes, or make your own stock without added salt.
- Taste your food first, do not automatically add extra salt.
Effects of having too much salt
Having too much salt is linked to high blood pressure. This raises your risk of serious problems like strokes and heart attacks.
Zinc
Zinc helps with:
- making new cells and enzymes
- processing carbohydrates, fat and protein in food
- wound healing
Good sources of zinc
Good sources of zinc include:
- meat
- shellfish
- dairy foods – such as cheese
- bread
- cereal products – such as wheatgerm
How much zinc you need
The amount of zinc you need is about:
- 9.5mg a day for men (aged 19 to 64 years)
- 7mg a day for women
You should be able to get all the zinc you need from your daily diet.
If you take zinc supplements, do not take too much as this could be harmful. Do not take more than 25mg of zinc supplements a day unless advised to by your GP.
Effects of taking too much zinc
Taking high doses of zinc reduces the amount of copper the body can absorb. This can lead to anaemia and a weakening of the bones.
Content supplied by the NHS and adapted for Ireland by the HSE
