Iodine helps make thyroid hormones, which help keep cells and the metabolic rate (the speed at which chemical reactions take place in the body) healthy.

Good sources of iodine

Good food sources of iodine include:

• sea fish
• 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 140 micrograms (μg) of iodine a day.

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

If you are following a strict vegan diet and do not eat any fish then you may want to consider taking an iodine supplement. Some types of plant-based milk are also fortified with iodine. If you are considering taking a supplement seek advice from a healthcare professional.

The Vegan Society has more information about iodine and vegan diets.

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.

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

Taking 0.5mg or less a day of iodine supplements is unlikely to cause any harm.

What does the Department of Health and Social Care advise?

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

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

Taking 0.5mg or less a day of iodine supplements is unlikely to cause any harm.

Iron is important in making 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 (but avoid this during pregnancy)
• red meat
• beans, such as red kidney beans, edamame beans and chickpeas
• nuts
• dried fruit – such as dried apricots
• fortified breakfast cereals
• soy bean flour

How much iron do I need?

The amount of iron you need is:

• 8.7mg a day for men over 18
• 14.8mg a day for women aged 19 to 50
• 8.7mg a day for women over 50

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

Women who lose a lot of blood during their monthly period (heavy periods) are at higher risk of iron deficiency anaemia and may need to take iron supplements.

Speak to a GP or a registered dietitian for more advice.

What happens if I take too much iron?

Side effects of taking high doses (over 20mg) of iron include:

• constipation
• feeling sick
• being sick
• stomach pain

Very high doses of iron can be fatal, particularly if taken by children, so always keep iron supplements out of the reach of children.

What does the Department of Health and Social Care advise?

Most people should be able to get all the iron they need by eating a varied and balanced diet. If you take iron supplements, do not take too much as this could be harmful.

Taking 17mg or less a day of iron supplements is unlikely to cause any harm. But continue taking a higher dose if advised to by a GP.