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.

Depleted soils

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).

Ultra-processed foods

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.

Overcooking

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).

Pace of life

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.

Digestive disorders

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.

Micronutrient deficiencies do not usually appear suddenly. They can develop gradually and manifest themselves in symptoms that are sometimes mistakenly attributed to stress.

• Persistent fatigue: feeling of low energy, even after a night's sleep, which may indicate a less efficient energy metabolism

• Digestive problems: intestinal discomfort, bloating, or difficult digestion, which may be linked to an imbalance of certain micronutrients that play a role in digestive functions.

• Decreased concentration: difficulty maintaining attention, feeling of mental fog or cognitive slowness in daily life

• Increased susceptibility to infections: more frequent infections or slower recovery, which may indicate weakened natural defenses

• Changes in skin, nails, or hair: duller skin, brittle nails, or excessive hair loss, which can sometimes be associated with insufficient micronutrient intake

Taken individually, these signs can have multiple causes. Their combination or persistence over time may raise questions about the overall balance of micronutrient intake, always within a comprehensive and individualised approach.

Dietary supplements

Iron

Iron is a mineral that is essential for the proper functioning of the body. It is involved in oxygen transport, energy metabolism, and red blood cell formation. Insufficient intake can result in persistent fatigue or decreased vitality.

Iron supplementation may be considered when dietary intake is insufficient or in cases of increased needs, within an appropriate and supervised framework.

This Iron Bisglycinate combines a patented chelated form, Ferrochel®, known for its good bioavailability and digestive tolerance, with PureWay-C® vitamin C, which promotes iron absorption. Just one capsule per day provides 100% of the recommended daily intake of iron and vitamin C.

Precautions for use: for adults only. Not a substitute for a varied and balanced diet or a healthy lifestyle. Do not exceed the recommended daily dose. Not recommended for people with abnormal iron accumulation (hemochromatosis, polycythemia, etc.). Pregnant or breastfeeding women should seek the advice of a healthcare professional before taking any supplements. Keep out of reach of young children.

Magnesium

It is an essential mineral that contributes to energy metabolism, nervous system function, and muscle function. Supplementation may be considered when dietary intake is insufficient or in cases of specific needs, such as during periods of fatigue or stress.

This triple magnesium combines three complementary forms of magnesium to promote good bioavailability and cover the most commonly recommended daily intake.

Precautions for use: for adults only. Not a substitute for a varied and balanced diet or a healthy lifestyle. Do not exceed the recommended daily dose. Pregnant or breastfeeding women should seek the advice of a healthcare professional. Magnesium may have a laxative effect in some people. In case of thyroid disorders, medical advice is recommended.

Zinc

Zinc is a trace element that is involved in many biological functions in the body. In particular, it contributes to the functioning of the immune system, protects cells against oxidative stress, and maintains normal skin, hair, and nails. Dietary intake may be insufficient in certain situations, particularly when the diet is predominantly plant-based or lacks diversity.

Zinc supplementation may then be considered to support micronutritional balance.

Precautions for use: for adults only. Not a substitute for a varied and balanced diet or a healthy lifestyle. Do not exceed the recommended daily dose. Recommended for use over a limited period of a few weeks to a few months. Pregnant or breastfeeding women should seek the advice of a healthcare professional before taking any supplements. Keep out of reach of young children.

Vitamin D3

Vitamin D is an essential vitamin that contributes to several physiological functions, including normal immune system function, calcium and phosphorus absorption, and the maintenance of bone and muscle function. It is partly synthesised by the body under the action of the sun, which can lead to insufficient intake when sun exposure is limited.

Vitamin D3 supplementation may then be considered to support micronutritional balance, particularly during certain times of the year or in situations where needs are increased.

Precautions for use: keep out of reach of children. Not a substitute for a varied and balanced diet or a healthy lifestyle. Do not exceed the recommended daily dose. Not for use in children under 3 years of age. Pregnant or breastfeeding women should seek the advice of a healthcare professional before taking any supplements. Professional advice is also recommended for any supplementation in children.

Some people may be at greater risk of insufficient micronutrient intake or less efficient absorption. These profiles do not automatically indicate a proven deficiency, but they do call for particular vigilance regarding micronutritional balance.

• Specific diets: vegetarian, vegan, or gluten-free diets can limit the intake of certain micronutrients, especially when the diet lacks diversity or when certain food combinations reduce their absorption.

• Periods of increased needs: Pregnancy, breastfeeding, intense physical activity, chronic stress, and ageing can increase the body's micronutrient requirements, sometimes beyond what is usually covered by diet.

• Digestive disorders or digestive surgery: Digestive disorders, intestinal inflammation, or bariatric surgery can disrupt the absorption of vitamins and minerals, even when dietary intake is theoretically sufficient.

• Drug or food interactions: Certain medications or food combinations can reduce the bioavailability of micronutrients, such as drinking tea with meals in the case of iron, or long-term treatments that can interfere with the absorption of certain nutrients.

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. 

Desired effect

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.

Dosage

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.

Contraindications

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.

Rather than waiting for the signs to appear, the most useful approach is often to act early: diversify your diet, take care of your sleep, and identify what in your daily life is depleting your reserves. Micronutrition is part of this proactive approach to health: correcting subtle imbalances before they become problematic. If you're unsure, start simple: one target at a time (fatigue, stress, sun exposure), for a limited period, and see what difference it really makes.

Solène Bonnet, former editorial director of Marie Claire Idées, brings specialised expertise in editorial strategy and writing. For eight years, she led the editorial team, ensuring the production of innovative content. As a mother of two, she pays particular attention to product ingredients and all the little details that can improve daily life. Passionate about an authentic and health-conscious approach, Solène favours products with healthy ingredients that align with an eco-friendly philosophy.