The Minerals ?
Like vitamins, minerals (or mineral salts) are essential substances for the proper functioning of the body. Most are found in unlimited quantities in nature, in the water of rivers, lakes and oceans, as well as in the soil.
There are 22 in total, which make up about 4% of our body mass, and which are classified into two categories.
Trace elements and major minerals
Called thus because they require contributions higher than 100 mg per day, there are 7 different which are: calcium, magnesium, potassium, phosphorus, sulfur, sodium and chlorine.
Called so because they are found in traces, and they together represent less than 15 g of the total body mass, there are 15 in total, among which are mainly: iron, zinc, copper, fluorine, iodine, chromium and selenium.
Minerals fulfill essential functions:
- At the level of metabolism: they are part of the composition of enzymes and hormones.
- At the level of the structure of the organism: they play a key role in the constitution of bones and teeth.
- At the level of the functions of the organism: they contribute to the maintenance of the cardiac rhythm, the muscular contraction, the neuronal conductivity and the acid-base balance.
In addition to the proteins, fats and carbohydrates that we have already seen in our previous lessons, our body needs vitamins for our cells to function properly.
Unlike macronutrients, these substances (called micronutrients because our bodies need them in small or very small quantities) have no energy value.
They are nonetheless essential, because they exercise primordial functions in all the biochemical processes of the organism: among other things, they regulate metabolism, facilitate the release of energy, and perform important functions in bone synthesis and fabrics.
With the exception of vitamin D (which can be synthesized after exposure to the sun, in certain latitudes) and vitamin K, the body is unable to synthesize vitamins: they must imperatively be provided by food.
There are 13 different vitamins, which we classify into two groups.
These are vitamin C and group B vitamins (B1, B2, B3 or PP, B5, B6, B8, B9 and B12).
They are so called because they are soluble in water, and therefore disperse in body fluids, without being stored: this factor makes them very little toxic, since even in case of overconsumption, they are evacuated in the urine. It also means that if the diet does not regularly provide more than 50% of the recommended intake, small deficiencies can develop within a month. Their maximum effect in the body occurs 8 to 14 hours after ingestion.
In general, water-soluble vitamins are mainly provided by fruits and vegetables (which are full of water).
These are vitamins A, D, E and K.
They are so called because they are dissolved and stored in the fatty tissue, which can make them toxic in high doses. This property also means that they can be supplied on a less regular basis than water-soluble vitamins.
In general, fat-soluble vitamins are provided by food lipids (oils, fatty fish, egg yolks, organ meats, liver, etc.), with the exception of vitamin D, the only really interesting source of which is the sun.
Are our daily intake of vitamins and minerals sufficient?
In theory, a balanced diet should provide all the vitamins and minerals the body needs.
But, while today in industrialized countries, severe deficiencies are rare, insufficiencies remain common. Numerous international studies have shown that large proportions of the population do not receive the recommended daily intakes for certain micronutrients: we can cite, among others, the Nutrition-Canada Survey, the two First National Health and Nutrition Examination Survey (NHANES I and NHANES II) and the Nationwide Food Consumption Survey in the United States, the Heidelberg Nutrition and Health Study in Germany, as well as the Dietary and Nutritional Survey of British Adults in England.
In France, several studies have evaluated the vitamin and mineral intake of French people. These are ESVITAF studies (Survey on the vitamin status of the French) conducted in 1985, the Bourgogne study (Vitamin status of healthy subjects in Burgundy) in 1996, the Val-de-Marne survey in 1991, and the famous SUVIMAX study in 1998 and then in 2012 (SUVIMAX 2).
→ Verdict: for most vitamins, the deficit (i.e. daily intakes less than half the necessary intakes) affects 10 to 50% of the population.
For vitamin D, the deficit would affect, according to studies, between 80 and 90% of the population in winter.
All of these studies therefore converge and point to the fact that a large number of people do not receive sufficient intakes of vitamins and minerals.
Why is food alone not enough?
Because the quality of what we eat has changed a lot
Industrial treatments: the vast majority of the foods consumed in our modern societies go through this type of treatment (pre-cutting, pre-washing, pre-cooking, ionization, pasteurization, etc.), which inevitably contribute to reducing the micronutrient contents.
Intensive agriculture: it is responsible for a depletion of soil nutrients, which can therefore no longer be found in plants.
Additives and pollutants: they also reduce antioxidant levels.
Because other factors increase our needs
Many other factors that we face most of the time lead to an increased need for vitamins and minerals:
Stress: urinary excretion of magnesium is accelerated when we are under stress (whatever it is), thereby increasing our needs for this nutrient.
Smoking (including passive smoking): tobacco destroys an important part of our vitamin C, and contributes to deteriorate our vitamin E, our vitamins B9 and B12, and our carotene.
Pollution: it reduces our ability to properly synthesize vitamin D when exposed to the sun, and makes us deplete antioxidant vitamins.
Sport: our needs for magnesium, zinc, vitamins B1, B6, C and E, and sometimes iron, are increased.
The sun: the β-carotene content of our skin decreases during too long exposure.
Age: our absorption and synthesis capacities diminish over the years, and our defense systems require greater amounts of antioxidant vitamins, vitamin B6, magnesium, zinc and selenium, to protect us properly against aggression exterior.
Medicines: hormonal treatments, anticoagulants or antiepileptics, to name a few, can reduce the absorption of certain micronutrients, interfere with their metabolism or accelerate their catabolism.
So how do you get adequate amounts of vitamins and minerals?
Balanced diet as the number 1 objective!
These micronutrient intakes must first come from your diet.
Vegetables Consequently, if this is not already the case, it is important to adapt it, by favoring foods with high nutritional density, that is to say foods that contain large amounts of interesting nutritional compounds for health, for a given number of calories: among them are fruits and vegetables, dry oilseeds, organ meats, seafood, etc.
Conversely, foods with a high caloric density often have a low nutritional density: fatty and sweet processed products, refined cereals, etc.
Most often, foods with a high nutritional density will at the same time be rich in antioxidants, in particular the plants in which they cooperate to protect them from free radicals, and act in the same way in our body.
In addition, by increasing the share of fruits and vegetables, you will at the same time help to fight against chronic acidosis, which greatly promotes osteoporosis, muscle wasting and high blood pressure.
The question of supplementation
Multivitamins All that being said, as we have just seen above, it sometimes seems difficult to ask a single diet to meet all the micronutrient needs, and a perfectly balanced diet, if it remains an ideal, is often complicated to achieve …
In reality, our modern diet generally provides a minimum of vitamins so that our body does not manifest acute symptoms, but the deficits caused most often have long-term repercussions, and are harmful to health. This is particularly what is shown by intervention studies using vitamins and minerals that improve health or performance.
Depending on your personal situation, it may then be advisable to use micronutrient supplementation, daily or circumstantial, in order to compensate for the limits of modern food, and thus preserve your health.
Complete customization of your needs may require a blood test and monitoring by a professional specialized in nutrition.