Vitamins and minerals are essential micronutrients for the proper metabolic functioning of the body. Deficiency of a single micronutrient can disrupt entire metabolic functioning .
Daily needs have been estimated to fulfill all the functions of the body . They will vary according to sex, age and way of life (sedentary, occasional sportsmen, high-level sportsmen, etc.).
A balanced and varied diet can meet these needs. Unfortunately, it is very difficult to have a power supply at the cutting edge of optimization. Intensive agriculture has led to soil depletion which affects the nutritional profile of foods, especially fruits and vegetables. Food intolerances disrupt the absorption of nutrients at the intestinal level. Overconsumption of refined foods, devoid of vitamins and minerals , has no nutritional advantage and takes the place of foods with more interesting profiles.
Stress , responsible for the secretion of cortisol, will also disrupt the metabolic functions of the body.
Today, many food supplements have been put on the market to compensate for one or more deficiencies. Beyond this problem was born nutraceuticals. Nutraceuticals were born from a real desire to restore physiological balance. However, due to this growing market, many companies are trying to promote themselves by offering products that are each richer in vitamins and minerals than the others. This approach is part of a quantitative context, forgetting to limit oneself to basic nutritional needs .
Concept of nutritional needs
Nutritional needs are defined in 3 levels.
The minimum intake , to avoid deficiencies, undernutrition and growth problems. The maximum intake , beyond which some toxicity may appear. And a contribution considered optimal.
Since 2005, the EFSA has been studying the dietary needs of each individual (children, adolescents, pregnant or breastfeeding women, athletes, etc.). These studies lead to the definition of NRVs (Nutritional Reference Values) which will make it possible to express daily nutritional needs . In France , these values are used by ANSES (National Agency for Food, Environmental and Occupational Health Safety) to define food labeling standards .
Labeling of dietary supplements
You have certainly been able to see, on many food supplements, the following information: 90% VNR; 100% NRV; 150% VNR… This indicates the percentage of a nutrient, present in the product, compared to its nutritional reference value . One might think that 100% of the NRVs are necessary and sufficient to meet the daily intake. Reality is more complex. A nutrient can be supplemented in different forms (citrate…, sulphate…, bisglycinate…, monohydrate, oxide…). These forms will not provide the same rate of absorption of the nutrient in question. In addition, some will be voluntarily added to substances, cofactors, which will help the assimilation of the nutrient by our body (example: zinc + magnesium + vitamin B6).
It is also possible that external elements disturb this assimilation , this is the case of the anti-nutrients present in certain raw fruits and vegetables for example, or the taking of certain drugs or diuretics inducing a loss of nutrients . It is not enough simply to seek the highest NRV rate to ensure optimal health!
The risks of toxicity
A food supplement will be subject to many regulations before it is placed on the market to rule out any risk of toxicity . However, if you decide to supplement for no real reason, then the supply of nutrients present in the food supplement that will supplement your diet may present a risk of overdose for your body. It is essential to take the contributions as a whole and not to make the mistake of neglecting the food part.
A food supplement is there to add to the diet, and this, in a non-systematic way. We do not eat food supplements !
Liebig's law is the law of minimum defined in plant physiology. It sets out the conditions under which a plant must grow. If one of the conditions is not met, then the plant will not be able to develop. It is illustrated by the image of a barrel whose shortest stave (representing one of the conditions necessary for the development of the plant) determines the level of filling.
This law, also called the law of limiting factors , explains that there is no point in feeding a plant abundantly if one of the nutrients is missing. Like this barrel, there is no point in filling it with water if all the conditions are not met. This principle can be extrapolated to humans, insofar as it is essential to provide micronutrients in the right proportions, according to their needs. It is therefore not necessary to go for amplified quantities, it is enough to have the right quantity of each element to benefit from optimal metabolic functioning .