B vitamins and folic acid - Vitamins and minerals

There are many different types of vitamin B.

This section has information on:

  • thiamin (vitamin B1)
  • riboflavin (vitamin B2)
  • niacin (vitamin B3)
  • pantothenic acid
  • vitamin B6
  • biotin (vitamin B7)
  • folate and folic acid
  • vitamin B12

Thiamin (vitamin B1)

Thiamin, also known as vitamin B1, helps:

  • the body break down and release energy from food
  • keep the nervous system healthy

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 as this might be harmful. Taking 100mg or less a day of thiamin supplements is unlikely to cause any harm.

Good sources of thiamin

Thiamin is found in many types of food.

Good sources include:

  • peas
  • some fresh fruits (such as bananas and oranges)
  • nuts
  • wholegrain bread
  • some fortified breakfast cereals
  • liver

How much thiamin you need

The amount of thiamin adults aged 19 to 64 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.

Your body cannot store thiamin, so you need it in your diet every day.

Riboflavin (vitamin B2)

Riboflavin, also known as vitamin B2, helps:

  • to keep skin, eyes and the nervous system healthy
  • the body release energy from food

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 many as this might be harmful. Taking 40mg or less a day of riboflavin supplements is unlikely to cause any harm.

Good sources of riboflavin

Good sources of riboflavin include:

  • milk
  • eggs
  • fortified breakfast cereals
  • mushrooms
  • plain yoghurt

UV light can destroy riboflavin, so try to keep these foods out of direct sunlight.

How much riboflavin you need

The amount of riboflavin adults aged 19 to 64 need is about:

  • 1.3mg a day for men
  • 1.1mg a day for women

You should be able to get all the riboflavin you need from your daily diet.

Your body cannot store riboflavin, so you need it in your diet every day.

Niacin (vitamin B3)

Niacin, also known as vitamin B3, helps:

  • the body release energy from food
  • to keep the nervous system and skin healthy

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 as 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.

Good sources of niacin

There are 2 forms of niacin: nicotinic acid and nicotinamide. Both are found in food.

Good sources of niacin include:

  • meat
  • fish
  • wheat flour
  • eggs

How much niacin you need

The amount of niacin you need is about:

  • 16.5mg a day for men
  • 13.2mg a day for women

You should be able to get all the niacin you need from your daily diet.

Your body cannot store niacin, so you need it in your diet every day.

Effects of taking 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.

Pantothenic acid

Pantothenic acid has several functions, such as helping the body to release energy from food.

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.

Good sources of pantothenic acid

Pantothenic acid is found in different amounts in almost all vegetables, wholegrain foods and meats.

Good sources include:

  • chicken
  • beef
  • liver and kidneys
  • eggs
  • mushrooms
  • avocados

Breakfast cereals that are fortified with pantothenic acid are also a good source.

How much pantothenic acid you need

No amount has been set in Ireland for how much pantothenic acid you need.

You should be able to get all the pantothenic acid you need from your daily diet, as it's found in many foods.

Your body cannot store pantothenic acid, so you need it in your diet every day.

Vitamin B6

Vitamin B6, also known as pyridoxine, helps:

  • the body to use and store energy from protein and carbohydrates in food
  • the body form haemoglobin, the substance in red blood cells that carries oxygen around the body

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 as this could be harmful. Do not take more than 10mg of vitamin B6 a day in supplements unless advised to by your doctor.

Good sources of vitamin B6

Vitamin B6 is found in a wide variety of foods, including:

  • pork
  • poultry, such as chicken or turkey
  • some fish
  • peanuts
  • soya beans
  • wheatgerm
  • oats
  • bananas
  • milk
  • some fortified breakfast cereals

How much vitamin B6 you need

The amount of vitamin B6 adults 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.

The bacteria that live naturally in your bowel can make vitamin B6.

Effects of taking too much vitamin B6

When taking a supplement, it's important not to take too much.

Taking 200mg or more a day of vitamin B6 can lead to a loss of feeling in the arms and legs. This is called peripheral neuropathy.

This will usually improve when you stop taking the supplements.

In rare cases when people have taken large amounts of vitamin B6, particularly for more than a few months, the effect can be permanent.

The effect of taking vitamin B6 at doses between 10 and 200 mg is unclear. There's not enough evidence to say for how long someone could take these doses safely.

Biotin (vitamin B7)

Biotin is needed in very small amounts to help the body make fatty acids.

The bacteria that live naturally in your bowel can make biotin. So it's not clear if you need any additional biotin from your diet.

Biotin is also found in a wide range of foods, but only at very low levels.

You should be able to get all the biotin you need by eating a varied and balanced diet.

If you take biotin supplements, do not take too much as this might be harmful. Taking 0.9mg or less a day of biotin in supplements is unlikely to cause any harm.

Folate and folic acid

Folate is a B vitamin found in many foods. The manmade form of folate is folic acid.

Folate is also known as folacin and vitamin B9.

Folate helps:

  • the body form healthy red blood cells
  • reduce the risk of birth defects called neural tube defects in unborn babies, such as spina bifida

A lack of folate could lead to folate deficiency anaemia.

If you're pregnant or could get pregnant, it's recommended that you take folic acid supplements.

Other people should be able to get all the folate they need by eating a varied and balanced diet.

If you're taking folic acid supplements, it's important not to take too much as this could be harmful. Taking 1mg or less a day of folic acid supplements is unlikely to cause any harm.

Good sources of folate

Folate is found in small amounts in many foods.

Good sources include:

  • broccoli
  • brussels sprouts
  • leafy green vegetables, such as cabbage, kale, spring greens and spinach
  • peas
  • chickpeas and kidney beans
  • liver (but avoid this during pregnancy)
  • breakfast cereals fortified with folic acid

How much folate you need

Adults need 200 micrograms of folate a day. 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).

Your body cannot store folates long-term, so you need to eat folate-containing foods often.

Most people should be able to get the amount of folate they need by eating a varied and balanced diet.

If you're pregnant or you could get pregnant

If you're pregnant, trying for a baby or you could get pregnant, you should take a 400 microgram folic acid supplement daily until you're 12 weeks pregnant.

You need to take folic acid supplements before you get pregnant, so start taking them before you stop using contraception or if there's a chance you might get pregnant.

This is to help prevent neural tube defects, such as spina bifida, in your baby.

If you're at high risk of having a pregnancy affected by a neural tube defect, you are advised to take 5mg of folic acid each day until you're 12 weeks pregnant.

This is important and unlikely to cause harm, as it's taken on a short-term basis, but talk to your GP first.

Get advice about vitamins and minerals during pregnancy

Effects of taking too much folic acid

Taking doses of folic acid higher than 1mg can mask the symptoms of vitamin B12 deficiency. This can eventually damage the nervous system if it's not spotted and treated.

This is a concern for older people because it becomes more difficult to absorb vitamin B12 as you get older.

Vitamin B12

Vitamin B12 is involved in helping the body:

  • make red blood cells and keeping the nervous system healthy
  • release energy from food
  • use folate

A lack of vitamin B12 could lead to vitamin B12 deficiency anaemia.

Good sources of vitamin B12

Good sources include:

  • meat
  • fish
  • milk
  • cheese
  • eggs
  • some fortified breakfast cereals

How much vitamin B12 you need

Adults aged 19 to 64 need about 1.5 micrograms 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.

Vitamin B12 is not found naturally in foods such as fruit, vegetables and grains, so vegans may not get enough of it.

Anaemia

In rare cases, you may have a condition called pernicious anaemia. This means that your body cannot absorb oral B12. Your GP can do a blood test to check for this condition.

If you take vitamin B12 supplements, do not take too much as this could be harmful.

Taking 2mg or less a day of vitamin B12 in supplements is unlikely to cause any harm.


Content supplied by the NHS and adapted for Ireland by the HSE

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This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.

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