Certain substances are essential for the survival of the human organism, but the body cannot manufacture them. Such substances are also known as essential nutrients. You have to supply these nutrients to the body from the outside. Ideally, this is done through a healthy and balanced diet. Essential nutrients include, for example, vitamins, minerals (including trace elements and bulk elements), essential amino acids and essential fatty acids.
Essential nutrients at a glance
The most important characteristic of essential substances is that the organism cannot synthesize them itself, although they are necessary for survival. Therefore, the body is dependent on an external supply. Essential nutrients are needed by the body in a form that it can utilize directly or in a precursor that it can process.
If essential nutrients are missing, deficiency symptoms are the result. If the deficiency is prolonged or severe, serious illnesses will result. These deficiency symptoms occur even when energy-bearing nutrients (protein, carbohydrates and fats) are available in sufficient quantities. Essential nutrients are therefore literally essential for a healthy diet and a strong immune system.
Determining the essentiality and the respective requirement of essential nutrients is methodologically difficult. Specific intake recommendations or the classification of a substance as essential are therefore the subject of constant debate in nutrition science. For certain essential nutrients, however, there is agreement that the human body is dependent on them to maintain its basic functions.
Vitamins are essential nutrients that the human organism either cannot synthesize itself or can synthesize only in insufficient quantities. This includes all fat-soluble and water-soluble vitamins. As essential substances, vitamins are vital to life. In the case of vitamin deficiency, many basic bodily functions no longer work. Certain metabolic processes are impossible without an adequate supply of vitamins.
For instance, vitamin A is essential for growth and vision and also plays an essential role in the renewal of body cells. Furthermore, it is also relevant for bones and teeth and is present in yellow fruits and vegetables. A well-known example is carrots. Likewise, vitamin A is found in dairy products. Vitamin D is an important micronutrient that ensures better transport of calcium and phosphate from food.
Vitamin D thus plays an important role in maintaining bone substance. In the diet, for example, egg yolk and saltwater fish provide a supply of vitamin D. The body can produce this vitamin itself.
Vitamin K plays a major role in blood clotting. This vitamin is present in green leafy vegetables, for example. Furthermore, cabbages and certain herbs (for example chives) contain vitamin K. With regard to all vitamins, it is true that deficiency symptoms and diseases can be the result of a lack of intake. However, an overdose is also problematic from a health point of view.
Certain essential nutrients belong to the group of minerals. Minerals include both bulk elements and trace elements. Bulk elements are basically essential nutrients. Among trace elements, only some are considered essential. The amount of minerals needed by the body is precisely regulated in the body. Minerals play an important role in various processes.
For example, magnesium is relevant for maintaining healthy muscle function. Magnesium is found in larger amounts in legumes, oatmeal, nuts and certain types of fruit (such as bananas). Calcium plays a key role in bone formation and in stabilizing cell membranes. This mineral is present in dairy products, for example. Potassium is a mineral that is involved in the body in regulating blood pressure and maintaining heart function. Potassium is present in larger quantities in legumes and cereals.
Trace elements are found in much smaller amounts in the human body (in trace amounts). Essential trace elements include iron, zinc, selenium, fluorine and iodine.
Iron is largely responsible for the transport of oxygen in the blood. It can be found in legumes, for example. Zinc plays a role in several bodily processes, for example in maintaining the immune system. You can find zinc in whole grain products and dairy products, for instance. Selenium is a trace element that contributes to the antioxidant protection of the human body. Moreover, it is found in larger quantities in Brazil nuts and also in cereals.
Essential amino acids
Certain amino acids are absolutely essential, while others are essential only under special conditions. Absolutely essential amino acids are lysine, threonine, isoleucine, methionine, valine, leucine, phenylalanine, tryptophan and histidine. Semiessential amino acids include thyrosine, arginine, glutamic acid and cysteine. The body cannot produce these by self-synthesis in certain situations, such as when the immune system is weakened by infection or fever.
Essential fatty acids
Essential fatty acids include linoleic acid and alpha-linolenic acid. If the intake is sufficient, further unsaturated fatty acids can be formed from these essential fatty acids by desaturation and chain extension. These subsequently no longer need to be supplied via the diet. Alpha-linolenic acid belongs to the group of omega-3 fatty acids. Omega-3 fatty acids contribute to the reduction of cardiovascular disease risks. They are mainly found in vegetable oils (for example linseed oil) and in many fish (especially salmon and anchovies).