Magnesium is a mineral found in a wide variety of foods. The richest sources are green leafy vegetables (such as spinach) and nuts. Good sources include bread, fish, meat and dairy foods.
You should be able to get all the magnesium you need from your daily diet. This is:
300 mg a day for men 270 mg a day for women
What does it do?
Magnesium has a number of important functions. For example it:
helps turn the food we eat into energy
helps make sure the parathyroid glands work normally. The parathyroid glands produce hormones important for bone health
What happens if I take too much?
Taking high doses of magnesium for a short time can cause diarrhoea.
There isn't enough evidence to say what the effects might be of taking high doses of magnesium for a long time.
What is FSA advice?
You should be able to get all the magnesium you need by eating a varied and balanced diet. But if you decide to take magnesium supplements it's a good idea not to take too much because this could be harmful.
Having 400 mg or less a day of magnesium from supplements is unlikely to cause any harm.
EVM review of magnesium (pdf 43KB)