Vitamins and minerals
Introduction
Vitamins and minerals
Vitamins and minerals are essential nutrients your body needs in small amounts to work properly.
Most people should get all the nutrients they need by eating a varied and balanced diet.
The pages in this section contain advice and information on vitamins, minerals and trace elements essential for health, including:
what they do
how much you need
what happens if you have too much
safety advice about supplements
Vitamin and mineral supplements
If you choose to take vitamin and mineral supplements, be aware that taking too many or for too long can cause harmful effects.
Some people may need to take vitamin and mineral supplements. For information on who could benefit from supplements, see Do I need vitamin supplements?
If you're trying to cut down on your salt intake, you might want to avoid vitamin and mineral supplements that come as effervescent or fizzy tablets, as they can contain up to 1g of salt per tablet.
What are vitamins?
There are two types of vitamins: fat-soluble and water-soluble.
Fat-soluble vitamins
Fat-soluble vitamins are found mainly in fatty foods and animal products, such as vegetable oils, milk and dairy foods, eggs, liver, oily fish and butter.
While your body needs these vitamins every day to work properly, you don't need to eat foods containing them every day.
This is because your body stores these vitamins in your liver and fatty tissues for future use. These stores can build up so they are there when you need them. However, if you have much more than you need, fat-soluble vitamins can be harmful.
Fat-soluble vitamins are:
vitamin A
vitamin D
vitamin E
vitamin K
Water-soluble vitamins
Water-soluble vitamins are not stored in the body, so you need to have them more frequently.
If you have more than you need, your body gets rid of the extra vitamins when you urinate. As the body does not store water-soluble vitamins, these vitamins are generally not harmful. However, this doesn't mean that all large amounts are necessarily harmless.
Water-soluble vitamins are found in a wide range of foods, including fruit, vegetables, potatoes, grains, milk and dairy foods. Unlike fat-soluble vitamins, they can be destroyed by heat or being exposed to the air. They can also be lost in water used for cooking.
This means that by cooking foods, especially boiling them, we lose some of these vitamins. The best way to keep as many of the water-soluble vitamins as possible is to steam or grill foods, rather than boil them, or to use the cooking water in soups or stews rather than pouring it away.
Water-soluble vitamins are vitamin C, the B vitamins and folic acid.
There are also many other types of vitamins and minerals that are an important part of a healthy diet.
What are minerals?
Minerals are necessary for three main reasons:
building strong bones and teeth
controlling body fluids inside and outside cells
turning the food you eat into energy
Minerals are found in foods such as meat, cereals (including cereal products such as bread), fish, milk and dairy foods, vegetables, fruit (especially dried fruit) and nuts.
Essential minerals include calcium and iron, although there are also many other types of minerals that are an important part of a healthy diet.
What are trace elements?
Trace elements are also essential nutrients that your body needs to work properly, but in much smaller amounts than vitamins and minerals.
Trace elements are found in small amounts in a variety of foods such as meat, fish, cereals, milk and dairy foods, vegetables and nuts.
Examples of trace elements are iodine and fluoride.
Vitamin A
Vitamin A is also known as retinol and has several important functions.
These include:
helping your immune system to work as it should against infections
helping vision in dim light
keeping skin and the linings of some parts of the body, such as the nose, healthy
Good sources of vitamin A
Good sources of vitamin A include:
cheese
eggs
oily fish
fortified low-fat spreads
milk and yoghurt
Liver is a particularly rich source of vitamin A, although this means you may be at risk of having too much vitamin A if you eat liver more than once a week (see below).
You can also contribute to your vitamin A intake by including good sources of beta-carotene in your diet, as this can be converted into vitamin A by the body. The main food sources of beta-carotene are:
yellow, red and green (leafy) vegetables, such as spinach, carrots, sweet potatoes and red peppers
yellow fruit such as mango, papaya and apricots
How much vitamin A do I need?
The amount of vitamin A adults need is:
0.7mg a day for men
0.6mg a day for women
You should be able to get all the vitamin A you need from your daily diet.
Any vitamin A your body doesn't need immediately is stored for future use. This means you don't need it every day.
What happens if I take too much vitamin A?
According to some research, having more than an average of 1.5mg a day of vitamin A over many years may affect your bones, making them more likely to fracture when you are older.
This is particularly important for older people, especially women, who are already at risk of osteoporosis. This is where your bone density reduces and you have a higher risk of fractures.
If you eat liver or liver pâté more than once a week, you may be getting too much vitamin A.
If you don't get enough vitamin D, you could be more at risk of the harmful effects of too much vitamin A. People who may be particularly at risk of not having enough vitamin D include:
all pregnant and breastfeeding women (see below)
all people aged 65 and over
people who are not exposed to much sun – for example, those who cover up their skin for cultural reasons, or those who are housebound or confined indoors for long periods
people with darker skin – such as people of African-Caribbean and South Asian origin
Many multivitamins contain vitamin A. Other supplements, such as fish liver oil, are also high in vitamin A. If you take supplements containing vitamin A, make sure your daily intake of vitamin A from food and supplements does not exceed 1.5mg. If you eat liver every week, don't take supplements that contain vitamin A.
If you are pregnant
Having large amounts of vitamin A can harm your unborn baby. Therefore, if you are pregnant or thinking about having a baby, do not eat liver or liver products, such as pâté, because these are very high in vitamin A.
Also, do not take supplements that contain vitamin A. Ask your GP or midwife if you would like more information.
What does the Department of Health advise?
You should be able to get all the vitamin A you need by eating a varied and balanced diet. If you take a supplement that contains vitamin A, don't take too much, because this could be harmful.
Liver is a very rich source of vitamin A. Do not eat liver or liver products, such as pâté, more than once a week. You should also be aware of how much vitamin A there is in any supplements you take.
If you are pregnant or thinking of having a baby:
do not take supplements containing vitamin A, including fish liver oil, unless advised to by your GP
do not eat liver or liver products, such as pâté, because these are very high in vitamin A
Women who have been through the menopause and older men, who are more at risk of osteoporosis, should avoid having more than 1.5mg of vitamin A a day from food and supplements. This means:
not eating liver or liver products, such as pâté, more than once a week, or having smaller portions of these
taking no more than 1.5mg of vitamin A a day in supplements (including fish liver oil) if you do not eat liver or liver products
not taking any supplements containing vitamin A (including fish liver oil) if you eat liver once a week
Having an average of 1.5mg a day or less of vitamin A from diet and supplements combined is unlikely to cause any harm.
The B vitamins
There are many different types of vitamin B and they all have important functions.
This section has information on:
thiamin (vitamin B1)
riboflavin (vitamin B2)
niacin (vitamin B3)
pantothenic acid
vitamin B6
folic acid
vitamin B12
Thiamin (vitamin B1)
Thiamin is also known as vitamin B1. It has several important functions, including:
working with other B-group vitamins to help break down and release energy from food
keeping the nervous system healthy
Good sources of thiamin
Thiamin is found in most types of food. Good sources include:
vegetables – such as peas
fresh and dried fruit
eggs
wholegrain breads
some fortified breakfast cereals
liver
How much thiamin do I need?
The amount of thiamin you need is:
1mg a day for men
0.8mg a day for women
You should be able to get all the thiamin you need from your daily diet.
Thiamin cannot be stored in the body, so you need it in your diet every day.
What happens if I take too much thiamin?
There is not enough evidence to know what the effects might be of taking high doses of thiamin supplements each day.
What does the Department of Health advise?
You should be able to get all the thiamin you need by eating a varied and balanced diet. If you take supplements, do not take too much because this might be harmful.
Taking 100mg or less a day of thiamin supplements is unlikely to cause any harm.
Riboflavin (vitamin B2)
Riboflavin is also known as vitamin B2. Its functions include:
keeping skin, eyes and the nervous system healthy
helping the body release energy from the food we eat
Good sources of riboflavin
Good sources of riboflavin include:
milk
eggs
fortified breakfast cereals
rice
UV light can destroy riboflavin, so ideally these foods should be kept out of direct sunlight.
How much riboflavin do I need?
The amount of riboflavin you need is about:
1.3mg a day for men
1.1mg a day for women
Riboflavin cannot be stored in the body, so you need it in your diet every day.
You should be able to get all the riboflavin you need from your daily diet.
What happens if I take too much riboflavin?
There is not enough evidence to know what the effects might be of taking high doses of riboflavin supplements each day.
What does the Department of Health advise?
You should be able to get all the riboflavin you need by eating a varied and balanced diet. If you take supplements, do not take too much, because this might be harmful.
Taking 40mg or less a day of riboflavin supplements is unlikely to cause any harm.
Niacin (vitamin B3)
Niacin is also known as vitamin B3. It has several important functions, including:
helping to release energy from the foods we eat
helping to keep the nervous systems and skin healthy
Good sources of niacin
There are two forms of niacin – nicotinic acid and nicotinamide – both of which are found in food.
Good sources of niacin include:
meat
fish
wheat flour
eggs
milk
How much niacin do I need?
The amount of niacin you need is about:
17mg a day for men
13mg a day for women
You should be able to get all the niacin you need from your daily diet.
Niacin cannot be stored in the body, so you need it in your diet every day.
What happens if I take too much niacin?
Taking high doses of nicotinic acid supplements can cause skin flushes. Taking high doses for a long time could lead to liver damage.
There is not enough evidence to know what the effects might be of taking high daily doses of nicotinamide supplements.
What does the Department of Health advise?
You should be able to get the amount of niacin you need by eating a varied and balanced diet. If you take niacin supplements, do not take too much because this might be harmful.
Taking 17mg or less of nicotinic acid supplements a day or 500mg or less of nicotinamide supplements a day is unlikely to cause any harm.
Pantothenic acid
Pantothenic acid has several functions, such as helping to release energy from the food we eat.
Good sources of pantothenic acid
Pantothenic acid is found in virtually all meat and vegetable foods, including:
chicken
beef
potatoes
porridge
tomatoes
kidney
eggs
broccoli
wholegrains – such as brown rice and wholemeal bread
Breakfast cereals are also a good source if they have been fortified with pantothenic acid.
How much pantothenic acid do I need?
You should be able to get all the pantothenic acid you need from your daily diet.
Pantothenic acid cannot be stored in the body, so you need it in your diet every day.
What happens if I take too much pantothenic acid?
There is not enough evidence to know what the effects might be of taking high daily doses of pantothenic acid supplements.
What does the Department of Health advise?
You should be able to get all the pantothenic acid you need by eating a varied and balanced diet. If you take supplements, do not take too much, as this might be harmful.
Taking 200mg or less a day of pantothenic acid in supplements is unlikely to cause any harm.
Vitamin B6
Vitamin B6 is also known as pyridoxine. It has several important functions, including:
allowing the body to use and store energy from protein and carbohydrates in food
helping to form haemoglobin – the substance in red blood cells that carries oxygen around the body
Good sources of vitamin B6
Vitamin B6 is found in a wide variety of foods, such as:
pork
poultry (such as chicken or turkey)
fish
bread
whole cereals – such as oatmeal, wheat germ and brown rice
eggs
vegetables
soya beans
peanuts
milk
potatoes
some fortified breakfast cereals
How much vitamin B6 do I need?
The amount of vitamin B6 you need is about:
1.4mg a day for men
1.2mg a day for women
You should be able to get all the vitamin B6 you need from your daily diet. You need it in your diet every day, because it cannot be stored in the body.
What happens if I take too much vitamin B6?
Taking more than 200mg a day of vitamin B6 for a long time can lead to a loss of feeling in the arms and legs, known as peripheral neuropathy.
Generally, the symptoms are reversible, so once you stop taking supplements, the symptoms usually stop.
However, in a few cases, when people have taken large amounts of vitamin B6, especially for more than a few months, the effect has been irreversible.
Taking doses of 10-200mg a day for short periods may not cause any harm. However, there is not enough evidence to say for how long these doses could be taken safely.
What does the Department of Health advise?
You should be able to get the vitamin B6 you need by eating a varied and balanced diet. If you take vitamin B6 supplements, do not take too much, because this could be harmful.
Do not take more than 10mg of vitamin B6 a day in supplements, unless advised to by a doctor.
Folic acid
Folic acid, known as folate in its natural form, is one of the B-group vitamins.
Folic acid has several important functions. For example, it:
works together with vitamin B12 to form healthy red blood cells
helps to reduce the risk of central nervous system defects, such as spina bifida, in unborn babies
A lack of folic acid could lead to folate deficiency anaemia.
Good sources of folic acid
Folate is found in small amounts in many foods. Good sources include:
broccoli
brussels sprouts
liver
spinach
asparagus
peas
chickpeas
fortified breakfast cereals
How much folic acid do I need?
Adults need 0.2mg of folic acid a day.
Folic acid cannot be stored in the body, so you need it in your diet every day.
Most people should be able to get the amount they need by eating a varied and balanced diet.
However, if you are pregnant, thinking of trying to have a baby or likely to become pregnant, it is recommended that you take a 0.4mg (400 micrograms) folic acid supplement daily from the time you stop using contraception until the 12th week of pregnancy. This is to help prevent birth defects of the central nervous system, such as spina bifida, in your baby.
If you have a family history of conditions like spina bifida (known as neural tube defects), you may need to take a higher dose of 5mg of folic acid each day until the 12th week of pregnancy. This is available on prescription from your GP. Women with diabetes and those taking anti-epileptic medicines should speak to their GP for advice, as they may also need to take a higher dose of folic acid.
What happens if I take too much folic acid?
Taking doses of folic acid higher than 1mg can disguise vitamin B12 deficiency.
An early symptom of vitamin B12 deficiency is anaemia. However, taking large amounts of folic acid treats the anaemia without treating the B12 deficiency. If a vitamin B12 deficiency is not noticed, it can eventually damage the nervous system.
This is particularly a concern for older people, because it becomes more difficult to absorb vitamin B12 as you get older.
What does the Department of Health advise?
The Department of Health recommends that folic acid supplements are taken by women who are pregnant, thinking of having a baby or likely to become pregnant (see above).
Women who are not pregnant or planning for a baby should be able to get all the folate they need by eating a varied and balanced diet.
If you are taking folic acid supplements, it's important not to take too much, because this could be harmful.
Taking 1mg or less a day of folic acid supplements is unlikely to cause any harm.
Some women have an increased risk of having a pregnancy affected by a neural tube defect, and are advised to take a higher dose of 5mg of folic acid each day until they are 12 weeks pregnant. This is important and unlikely to cause harm, as it is taken on a short-term basis.
Vitamin B12
Vitamin B12 has several important functions and is involved in:
making red blood cells and keeping the nervous system healthy
releasing energy from the food we eat
processing folic acid
A lack of vitamin B12 could lead to vitamin B12 deficiency anaemia.
Good sources of vitamin B12
Good sources include:
meat
salmon
cod
milk
cheese
eggs
some fortified breakfast cereals
How much vitamin B12 do I need?
Adults need approximately 0.0015mg a day of vitamin B12.
If you eat meat, fish or dairy foods, you should be able to get enough vitamin B12 from your diet.
However, because vitamin B12 is not found naturally in foods such as fruit, vegetables and grains, vegans may not get enough of this vitamin.
What happens if I take too much vitamin B12?
There is not enough evidence to show what the effects may be of taking high doses of vitamin B12 supplements each day.
What does the Department of Health advise?
You should be able to get all the vitamin B12 you need by eating a varied and balanced diet. If you take vitamin B12 supplements, do not take too much, because this could be harmful.
Taking 2mg or less a day of vitamin B12 in supplements is unlikely to cause any harm.
Vitamin C
Vitamin C is also known as ascorbic acid and has several important functions.
For example, it:
helps to protect cells and keeps them healthy
is necessary for the maintenance of healthy connective tissue, which gives support and structure for other tissue and organs
helps wound healing
A lack of vitamin C can lead to scurvy.
Good sources of vitamin C
Vitamin C is found in a wide variety of fruit and vegetables. Good sources include:
oranges and orange juice
red and green peppers
strawberries
blackcurrants
broccoli
brussels sprouts
potatoes
How much vitamin C do I need?
Adults need 40mg of vitamin C a day.
Vitamin C cannot be stored in the body, so you need it in your diet every day.
You should be able to get all the vitamin C you need from your daily diet.
What happens if I take too much vitamin C?
Taking large amounts (more than 1,000mg per day) of vitamin C can cause:
stomach pain
diarrhoea
flatulence
These symptoms should disappear once you stop taking vitamin C supplements.
What does the Department of Health advise?
You should be able to get all the vitamin C you need by eating a varied and balanced diet. If you take vitamin C supplements, do not take too much, because this could be harmful.
Taking less than 1,000mg of vitamin C supplements is unlikely to cause any harm.
Vitamin D
Vitamin D has several important functions. For example, it helps to regulate the amount of calcium and phosphate in the body.
These nutrients are needed to keep bones and teeth healthy.
A lack of vitamin D can lead to bone deformities such as rickets in children, and bone pain and tenderness as a result of a condition called osteomalacia in adults.
Good sources of vitamin D
We get most of our vitamin D from sunlight on our skin. The vitamin is made by our body under the skin, in reaction to summer sunlight. However, if you are out in the sun, take care to cover up or protect your skin with sunscreen before you turn red or get burnt.
Vitamin D is also found in a small number of foods. Good food sources are:
oily fish – such as salmon, sardines and mackerel
eggs
fortified fat spreads
fortified breakfast cereals
some powdered milks
How much vitamin D do I need?
Most people should be able to get all the vitamin D they need by eating a healthy balanced diet and by getting some summer sun.
Groups of the population at risk of not getting enough vitamin D are:
all pregnant and breastfeeding women
babies and young children under the age of five
older people aged 65 years and over
people who are not exposed to much sun – such as people who cover up their skin when outdoors, or those who are housebound or confined indoors for long periods
people who have darker skin, such as those of African, African-Caribbean and South Asian origin
What does the Department of Health recommend?
The Department of Health recommends that:
all pregnant and breastfeeding women should take a daily supplement containing 10 micrograms (0.01mg) of vitamin D, to ensure the mother's requirements for vitamin D are met and to build adequate foetal stores for early infancy
all babies and young children aged six months to five years should take a daily supplement containing vitamin D in the form of vitamin drops, to help them meet the requirement set for this age group of 7-8.5 micrograms (0.007-0.0085mg) of vitamin D a day
babies fed infant formula will not need vitamin drops until they are receiving less than 500ml (about a pint) of infant formula a day, as these products are fortified with vitamin D
breastfed infants may need to receive drops containing vitamin D from one month of age, if their mother has not taken vitamin D supplements throughout pregnancy
People should also take a daily supplement containing 10 micrograms (0.01mg) of vitamin D if they:
are aged 65 years or over
aren't exposed to much sun – for example, those who cover up their skin for cultural reasons, who are housebound or confined indoors for long periods
You can buy single vitamin D supplements or vitamin drops containing vitamin D (for use by under-fives) at most pharmacies and supermarkets. Women and children who qualify for the Healthy Start scheme can get free supplements containing the recommended amounts of vitamin D.
See the Healthy Start website for more information on the scheme.
What happens if I take too much vitamin D?
If you take vitamin D supplements, do not take more than 25 micrograms (0.025mg) a day, as it could be harmful. However, taking less than this is unlikely to cause any harm.
Your body doesn't make too much vitamin D from sun exposure, but always remember to cover up or protect your skin if you are out in the sun for long periods.
Taking too many vitamin D supplements over a long period of time can cause more calcium to be absorbed than can be excreted.
The excess calcium can be deposited in and damage the kidneys. Excessive intake of vitamin D can also encourage calcium to be removed from bones, which can soften and weaken them.
Vitamin E
Vitamin E has several important functions. For example, it acts as an antioxidant, which protects cell membranes.
This helps to maintain healthy skin, eyes and strengthens the immune system.
Good sources of vitamin E
Vitamin E is found in a wide variety of foods. The richest sources are plant oils, such as soya, corn and olive oil.
Other good sources include:
nuts and seeds
wheat germ – found in cereals and cereal products
How much vitamin E do I need?
The amount of vitamin E you need is:
4mg a day for men
3mg a day for women
You should be able to get all the vitamin E you need from your daily diet.
Any vitamin E your body doesn't need immediately is stored for future use, so you don't need it in your diet every day.
What happens if I take too much vitamin E?
There isn't enough evidence to know what the effects might be of taking high doses of vitamin E supplements each day.
What does the Department of Health advise?
You should be able to get the amount of vitamin E you need by eating a varied and balanced diet. If you take vitamin E supplements, don't take too much.
Taking 540mg or less a day of vitamin E supplements is unlikely to cause any harm.
Vitamin K
Vitamin K has several important functions. For example, it's needed for blood clotting, which means it helps wounds to heal properly.
There's some evidence that vitamin K is also needed to help keep bones healthy.
Good sources of vitamin K
Vitamin K is found in:
green leafy vegetables – such as broccoli and spinach
vegetable oils
cereal grains
Small amounts can also be found in meat and dairy foods.
How much vitamin K do I need?
Adults need approximately 0.001mg a day of vitamin K for each kilogram of their body weight.
For example, someone who weighs 65kg would need 0.065mg a day of vitamin K, while a person who weighs 75kg would need 0.075mg a day.
You should be able to get all the vitamin K you need by eating a varied and balanced diet.
Any vitamin K your body doesn't need immediately is stored in the liver for future use, so you don't need it in your diet every day.
What happens if I take too much vitamin K?
There's not enough evidence to know what the effects might be of taking high doses of vitamin K supplements each day.
What does the Department of Health advise?
You should be able to get all the vitamin K you need by eating a varied and balanced diet. If you take vitamin K supplements, don't take too much, because this might be harmful.
Taking 1mg or less of vitamin K supplements a day is unlikely to cause any harm.
Calcium
There is more calcium in the body than any other mineral, and it has several important functions.
These include:
helping to build strong bones and teeth
regulating muscle contractions, including heartbeat
ensuring that blood clots normally
A lack of calcium could lead to a condition called rickets in children or osteoporosis in later life.
Good sources of calcium
Good sources of calcium include:
milk, cheese and other dairy foods
green leafy vegetables – such as broccoli, cabbage and okra, but not spinach
soya beans
tofu
soya drinks with added calcium
nuts
bread and anything made with fortified flour
fish where you eat the bones – such as sardines and pilchards
How much calcium do I need?
Adults need 700mg of calcium a day.
You should be able to get all the calcium you need from your daily diet.
What happens if I take too much calcium?
Taking high doses of calcium (over 1,500mg a day) could lead to stomach pain and diarrhoea.
What does the Department of Health advise?
You should be able to get all the calcium you need by eating a varied and balanced diet.
If you take calcium supplements, don't take too much. Taking 1,500mg or less a day is unlikely to cause any harm.
Iodine
Iodine helps to make the thyroid hormones. These hormones help to keep cells and the metabolic rate healthy.
Good sources of iodine
Iodine is a trace element found in seawater, rocks and some types of soil. Good food sources include sea fish and shellfish.
Iodine can also be found in plant foods, such as cereals and grains, but the levels vary, depending on the amount of iodine in the soil where the plants are grown.
How much iodine do I need?
Adults need 0.14mg of iodine a day.
Most people should be able to get all the iodine they need by eating a varied and balanced diet.
What happens if I take too much iodine?
Taking high doses of iodine for long periods of time could change the way your thyroid gland works. This can lead to a wide range of different symptoms, such as weight gain.
What does the Department of Health advise?
You should be able to get all the iodine you need by eating a varied and balanced diet. If you take iodine supplements, don't take too much, because this could be harmful.
Taking 0.5mg or less a day of iodine supplements is unlikely to cause any harm.
Iron
Iron is an essential mineral, with several important roles in the body.
For example, it helps to make red blood cells, which carry oxygen around the body.
A lack of iron can lead to iron deficiency anaemia.
Good sources of iron
Good sources of iron include:
liver
meat
beans
nuts
dried fruit – such as dried apricots
wholegrains – such as brown rice
fortified breakfast cereals
soybean flour
most dark-green leafy vegetables – such as watercress and curly kale
Although liver is a good source of iron, don't eat it if you are pregnant. This is because it is also rich in vitamin A which, in large amounts, can harm your unborn baby.
What does the Department of Health advise?
You should be able to get all the copper you need by eating a varied and balanced diet. If you take copper supplements, don't take too much, because this could be harmful.
Having 1mg or less a day of copper supplements is unlikely to cause any harm.
Magnesium
Magnesium is a mineral that, among other things:
helps turn the food we eat into energy
helps to make sure the parathyroid glands, which produce hormones that are important for bone health, work normally
Good sources of magnesium
Magnesium is found in a wide variety of foods, such as:
green leafy vegetables – such as spinach
nuts
brown rice
bread (especially wholegrain)
fish
meat
dairy foods
How much magnesium do I need?
The amount of magnesium you need is:
300mg a day for men
270mg a day for women
You should be able to get all the magnesium you need from your daily diet.
What happens if I take too much magnesium?
Taking high doses of magnesium (more than 400mg) for a short time can cause diarrhoea.
There is not enough evidence to say what the effects might be of taking high doses of magnesium for a long time.
What does the Department of Health advise?
You should be able to get all the magnesium you need by eating a varied and balanced diet. If you take magnesium supplements, don't take too much, because this could be harmful.
Having 400mg or less a day of magnesium from supplements is unlikely to cause any harm.
Manganese
Manganese is a trace element that helps make and activate some of the enzymes in the body.
Good sources of manganese
Manganese is found in a variety of foods, including:
tea – which is probably the biggest source of manganese for many people
bread
nuts
cereals
green vegetables – such as peas and runner beans
How much manganese do I need?
You should be able to get all the manganese you need from your daily diet.
Molybdenum
Molybdenum is a trace element that helps make and activate some of the enzymes involved in repairing and making genetic material.
What does the Department of Health advise?
You should be able to get all the nickel you need by eating a varied and balanced diet.
If you are allergic to nickel or think you might be, avoid taking nickel supplements.
The nickel found naturally in food should not cause any harm.
Phosphorus
Phosphorus is a mineral that helps to build strong bones and teeth, and helps to release energy from food.
Good sources of phosphorus
Phosphorus is present in many foods. Good sources include:
red meat
dairy foods
fish
poultry
bread
brown rice
oats
How much phosphorus do I need?
Adults need 550mg of phosphorus a day.
You should be able to get all the phosphorus you need from your daily diet.
What happens if I take 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, which means that bones are more likely to fracture.
What does the Department of Health advise?
You should be able to get all the phosphorus you need by eating a varied and balanced diet. If you take phosphorus supplements, it's important not to take too much, because this could be harmful.
Taking 250mg or less a day of phosphorus supplements is unlikely to cause any harm.
Good sources of silicon
Silicon is found in high levels in grains such as oats, barley and rice. It's also found in fruit and vegetables.
How much silicon do I need?
You should be able to get all the silicon you need from your daily diet.
How much zinc do I need?
The amount of zinc you need is about:
5.5-9.5mg a day for men
4.0-7.0mg a day for women
You should be able to get all the zinc you need from your daily diet.
What happens if I take too much zinc?
Taking high doses of zinc reduces the amount of copper the body can absorb. This can lead to anaemia and weakening of the bones.
What does the Department of Health advise?
You should be able to get all the zinc you need by eating a varied and balanced diet. If you take zinc supplements, it's important not to take too much, because this could be harmful.
Don't take more than 25mg of zinc supplements a day, unless advised to by a doctor.