Minerals

Minerals are inorganic nutrients that the body needs for bones, blood, nerves, muscles and countless metabolic processes. Like vitamins, they don't provide any energy. A distinction is made between macrominerals (the body contains a lot of these, more than 50 milligrams per kilogram: calcium, magnesium, potassium, sodium, phosphorus) and trace elements (tiny amounts: iron, iodine, zinc, selenium, fluoride).

The most important ones for families: calcium builds bones and teeth – the German Nutrition Society (DGE) recommends 1,000 milligrams a day for adults and as much as 1,200 for growing teenagers. A glass of milk or a pot of yoghurt provides around 300 milligrams, as do hard cheese, kale, broccoli and calcium-rich mineral water. Iron carries oxygen in the blood; girls and women need more than men because of menstruation. It's found in meat, pulses, oats and wholegrains – and iron from plant foods is absorbed much better together with vitamin C (peppers, oranges).

The thyroid needs iodine; Germany is an iodine-deficient region, which is why iodised table salt and sea fish are important. Magnesium from wholegrains, nuts and pulses supports muscles and nerves. Zinc strengthens the immune system and helps wounds heal.

When you're losing weight, your energy intake goes down, but your mineral requirements don't. If you keep dairy products, pulses, wholegrains, nuts and vegetables as the basis of your diet, you'll be well covered. Supplements only make sense if a deficiency has been confirmed – too much iron or zinc can even be harmful. A blood test at the paediatrician's or your GP's gives you certainty, for example if iron deficiency is suspected.