Minerals guide to magnesium, potassium, zinc and iodine and where to find them

Magnesium, found in the green and the brown

Magnesium contributes to a reduction of tiredness and fatigue and to normal muscle function. The NHS page on other vitamins and minerals gives the daily needs, which are 300mg for men and 270mg for women aged 19 to 64. Spinach, nuts and wholemeal bread are good sources. Brown rice and oats help too. Refined white versions lose much of it.

Potassium, the partner of salt

Adults need about 3500mg of potassium a day. Potassium contributes to the maintenance of normal blood pressure. Bananas are famous for it, yet potatoes with skins, beans, lentils, tomatoes, mushrooms and many vegetables supply plenty. Salt pulls the other way, and UK adults are advised to eat no more than 6g a day. The NHS guide to salt in your diet shows where it hides, mostly in bread, ready meals, sauces and processed meat. Cooking from scratch shifts the balance towards potassium almost by itself.

Zinc, small amounts that matter

Zinc contributes to the normal function of the immune system and to the maintenance of normal skin, hair and nails. Men need about 9.5mg a day and women about 7mg. Meat, shellfish, dairy, bread and cereal products all provide it. If you eat little meat, beans, seeds, nuts and wholegrains help fill the gap.

Iodine, the 1 that milk carries

Iodine contributes to normal thyroid function and to the normal production of thyroid hormones. In the UK much of it comes from milk, dairy and white fish, because iodine is not routinely added to table salt here. People who switch to plant drinks should check whether theirs is fortified. The BDA fact sheet on iodine explains who is most at risk of falling short, including women planning a pregnancy.

When eating less, keep the sources

A lighter diet can trim minerals if it cuts whole food groups. Dropping dairy removes calcium and iodine. Dropping bread and cereals removes some zinc and magnesium. The fix is to keep the groups and adjust portions. A breakfast of porridge with milk and a sprinkle of seeds already covers part of all 4.

Too much from pills

Food rarely causes an excess of these minerals, but high doses from pills can. The NHS warns, for example, that taking too much zinc reduces the copper the body can absorb. Unless your GP suggests otherwise, food remains the safer route. Our vitamins guide covers the same principle, and our article on macronutrients shows how minerals ride along with protein, carbohydrate and fat.

The club sits on the First Floor at 106 Churchill Road, and the free assessment there is a good moment to look at which food groups you might be leaving out.

Kidney conditions and some medicines change how the body handles potassium and other minerals. This article does not replace advice from your GP or another health professional.