The role of micronutrients in health, energy, and immunity

Micronutrients include vitamins, minerals, and trace elements that the body needs to function properly. They differ from macronutrients (carbohydrates, fats, and proteins), which provide energy in the form of calories. Micronutrients do not provide energy per se, but enable the body to use the energy it receives properly.

Found in very small quantities in food, micronutrients are involved in many internal processes that are essential for daily life. In particular, they contribute to metabolic reactions, cell function, and the regulation of many bodily functions. As the human body cannot produce most of these micronutrients, their intake depends directly on diet, and more specifically on the diversity and quality of the food consumed.

Although it is important to remember that a varied diet remains essential, it is not always sufficient on its own. The journal Nutrición Hospitalaria, based on data from the ANIBES study conducted among the Spanish population, highlights insufficient intakes of several key micronutrients, regardless of age (1). These deficiencies particularly concern certain vitamins, minerals, and trace elements, and can go unnoticed because they are not always accompanied by obvious signs in everyday life (2).

This situation is increasingly common because the way we eat and live has changed. Our soils are less rich in nutrients, many of the foods we eat are highly processed, and cooking methods can reduce vitamin and mineral content. On top of that, fast-paced lifestyles, certain medications, and digestive issues can make it harder for the body to absorb what it needs. Over time, all of this can gradually lower the body’s reserves of essential micronutrients.

Several factors can explain insufficient micronutrient intake or less efficient absorption by the body. In most cases, these causes are cumulative.

The nutritional quality of food depends largely on the quality of the soil in which it is grown. Over the decades, intensive agriculture and over-exploitation of the land have contributed to a decline in the mineral content of the soil. As a result, fruits, vegetables, and grains may contain fewer vitamins and minerals than before, even when consumed fresh and in sufficient quantities (3).

The growing role of ultra-processed foods in our daily diet is another important factor. Often high in calories but low in micronutrients (4), these products are gradually replacing raw foods that are natural sources of vitamins, minerals, and trace elements. This trend can lead to sufficient or even excessive energy (calorie) intake, without necessarily meeting micronutrient requirements.

Certain cooking practices can alter the micronutrient content of foods. Prolonged cooking or high temperatures can cause partial degradation of heat-sensitive vitamins, such as certain B vitamins and vitamin C (5).

Chronic stress, lack of sleep, or intense physical activity can increase the body's micronutrient requirements. In these situations, normal dietary intake may no longer be sufficient to compensate for high expenditure, creating an imbalance in the long term.

The absorption of micronutrients depends on the proper functioning of the digestive system. Intestinal inflammation or certain surgical procedures can disrupt the absorption of vitamins and minerals, even when dietary intake is theoretically sufficient. The bioavailability of micronutrients then becomes an essential factor.

Taking supplements is not about following a trend. It is part of a proactive approach to correcting imbalances that are sometimes difficult to detect on a daily basis. 

The aim of micronutrient supplementation is to meet a specific need that has been identified in advance. It is not a question of systematically increasing intake, but of supporting certain physiological functions when dietary intake or assimilation is no longer sufficient to meet the body's needs.

In micronutrition, the concept of the right dose is essential. Appropriate intakes support the body without overloading it, while excessive or poorly supervised supplementation can be useless. It is therefore recommended to follow the recommended dosages and to favour limited-time treatments tailored to individual circumstances.

Micronutrient supplementation is not suitable for all situations. Certain periods of life or personal circumstances require particular vigilance and may warrant professional advice. When in doubt, it is better to tailor supplementation to individual needs rather than resorting to a standardised approach.

Micronutrient supplementation is not a substitute for a varied and balanced diet or a healthy lifestyle. It is recommended to follow the recommended daily doses and avoid prolonged or cumulative intake without supervision. In case of pregnancy, breastfeeding, medication, or for any supplementation in children, professional advice is preferable.