We only take in tiny amounts of it through food – and yet the entire organism is dependent on it. Trace elements play an important role in countless metabolic processes in the body – a deficiency can have correspondingly serious consequences.
What are trace elements?
Trace elements (microelements) are nutrients that we only ingest in very small amounts (in traces) through food. Unlike the so-called bulk elements (macro elements), trace elements occur in amounts of less than 50 mg/kg body weight in the human organism. A distinction is made between essential (for the body’s indispensable) trace elements and non-essential (not urgently necessary) trace elements. Those who consume insufficient amounts of essential trace elements can develop deficiency symptoms.
Essential trace elements: the body needs these substances
The most important essential trace elements include:
Chromium: Essential for glucose metabolism
The trace element chromium plays an important role in regulating blood sugar. It is part of something called the glucose tolerance factor. This supports the hormone insulin in its work. Insulin causes the body’s cells to filter sugar from the blood and use it for energy, so blood sugar levels drop again after a meal. The glucose tolerance factor is therefore important for the regulation of blood sugar levels. Good sources of chromium are, for example, calf’s liver and wheat germ, as well as chicken and seafood.
Zinc supports the immune system
Zinc is involved in many metabolic processes in the body – for example in wound healing and the immune system. A zinc deficiency can therefore become noticeable through frequent colds or poor wound healing. Good suppliers of trace elements are, for example, meat, fish, seafood, cheese, lentils, oatmeal, and nuts. Zinc from plant sources is more difficult for the body to utilize than zinc from animal foods.
Selenium: trace element for the thyroid gland
The trace element selenium is needed in every single body cell. It is a building block for amino acids and enzymes and is involved in many processes in the body. Selenium probably plays the biggest role for the thyroid gland – it is the organ with the most selenium. The trace element also protects the cells from toxins and is therefore essential for the immune system. We also need selenium for healthy hair and nails. In men, it is also involved in sperm production.
In Europe, the soil is poor in selenium, which is why it can be mixed into animal feed. Meat (especially offal), eggs, or farmed fish are therefore rich in selenium, but Brazil nuts, lentils, rice, mushrooms, and dairy products also contain a lot of it. A selenium deficiency manifests itself, for example, in brittle hair, brittle nails, frequent infections, symptoms of thyroid malfunction, listlessness, tiredness, or sweating.
Iron: important for blood formation
Iron is an essential trace element for the entire organism: the body uses it as a “building block” to form new red blood cells. And these are responsible for supplying every single cell in the body with oxygen. This is why iron deficiency, which most often affects young women, manifests itself primarily in tiredness and poor concentration. Other typical signs are paleness and cracked corners of the mouth. Those affected often also suffer from hair loss, brittle fingernails, or headaches.
Optimal suppliers are meat, fennel, carrots, and spinach as well as millet, legumes, and nuts. Important: Vitamin C from fruit and vegetables promotes absorption. Simultaneous consumption of dairy products, coffee, or black tea, on the other hand, inhibits absorption.
Copper promotes immune defense and wound healing
The body needs copper primarily for the oxygen supply to the cells. The nutrient also strengthens the immune system and has a positive effect on wound healing. And copper has another important task: It ensures that the body can absorb the trace element iron well. Copper is abundant in peas, lentils, cocoa, shellfish, whole grains, and green vegetables.
Iodine: essential for the thyroid
The body needs iodine to form vital thyroid hormones. In Germany, iodine is added to table salt – iodized salt is said to prevent thyroid diseases such as cretinism (a disability caused by the mother’s iodine deficiency during pregnancy).
The reason why iodine has to be added is that the trace element is only found in small quantities in local soil. So we cannot absorb enough of it through drinking water. Most foods – except fish – also naturally contain little iodine, making it difficult to meet the requirement.