The primary function of food is to provide the body with energy to ensure its functioning. As key elements to preserve its physiological balance and protective substances to keep it in shape. But for it to be optimal, it is essential that it combines food in quantity and quality, while taking care to preserve the pleasure of eating. An equation that is not always easy to solve, given everyone’s lifestyles, environmental context and physiological fluctuations!
Two types of nutrients to distinguish
On closer inspection, it may be difficult, if not impossible, to cover the nutrient requirements for some of them and, which more is, for each of them through the plate alone. Either because the values to be reached assume the ingestion of disproportionate quantities of food, or because they are simply unachievable from a physiological point of view.
When we talk about nutrients, it is important to distinguish between:
- nutrients that provide energy such as carbohydrates, fats and proteins,
- to protect cells against damage from oxidative stress,
- to maintain nails and hair.
and the nutrients that contribute to the development and proper functioning of the body such as water, vitamins, minerals, fibers and micronutrients.
If the diet allows most of the time to easily cover the needs in supplier nutrients energy, it is more difficult to reach the recommended daily intake of vitamins, minerals and trace elements by this means alone. To be convinced of this, just look at a few examples of particularly essential nutrients, such as vitamin D, zinc or selenium, which play an important role in the immune system.
Vitamin D: difficult to cover the needs especially in the winter months
The AJR in vitamin D for an adult suppose, on a strictly dietary level and on the basis of the latest recommendations in force, a daily intake of the order of 10 at 15 µg (400 to 600 IU).
Vitamin D intake is quite low from the diet and can only be provided by ingestion of certain sources that are naturally high in fat (fatty fish, eggs, whole dairy products) or through fortified foods (oils, margarines, etc.).
The main source of vitamin D remains exposure to rays s of the sun (80 to 93% of contributions). This is not without problems in our country, especially between the months of October and March. This is why vitamin D deficiency is so prevalent, especially during the winter months.
Zinc: so important for the body and so rare in food
Zinc is a vital element for the body. It contributes to the normal functioning of the immune system, it is essential for cell growth and division (protein and DNA synthesis), it helps maintain normal fertility and contributes to the metabolism of macronutrients, fatty acids and vitamin A, etc Unfortunately, only 20 at 30% of zinc from food is absorbed by the body, which limits actual food intake. The zinc RDAs for an adult male are 10 mg/d, and 8 mg/d for adult women. That is a consumption equivalent to 70 g of wheat germ (12,6mg), 90 g oysters (14,4mg), 96 g of beef (14 .5 mg) or g of wholemeal bread (14,4 mg)!
Selenium: impossible to satisfy just by diet
Selenium is a very important nutrient for the body since it contributes, among other things:
to the normal functioning of the immune system ,
to the normal functioning of the thyroid,
The AJR in selenium are 70 mcg/d for men es and adult women. Just to cover these recommended daily intakes of selenium, it would be appropriate to eat the equivalent of 80 g of sardines (68 µg), 200 g oysters (72 µg), 190 g calf’s liver ( 80,2 µg) or more than 1 kg of wholemeal bread (68 µg)!
Furthermore, unfortunately, soil depletion of selenium (chemical fertilizer, acid rain, etc.) is a reality in Northern Europe. This is an unfavorable factor for the natural content of foods grown in these regions.
However, any deficit or insufficient intake exposes the body to a lower resistance to oxidative stress, to an increased risk of viral infections and the development of certain pathologies. Selenium being in particular a powerful antioxidant.
In view of these three examples, we observe that it is not so easy to provide the body with everything it needs, only by regularly having a varied, balanced and qualitative diet. This is why, in certain circumstances, it is wise to use food supplements to optimize intake and best protect health capital.
EFSA : Dietary Reference Values for nutrients Summary report
Presse Santé strives to transmit health knowledge in a language accessible to all. In NO CASE, the information given can not replace the advice of a health professional.
Do you like our content?
Receive our latest publications for free and directly in your inbox every day email
essential nutrients selenium zinc