Nutritional surveys tell us that the majority of populations in industrialized countries do not receive, through food, the recommended intakes of many minerals and vitamins.
The recommendations take into account three situations in which certain micronutrient requirements are very substantially increased:
- growth in children and adolescents;
- pregnancy and lactation in women;
- the third Age
It is recognized that in these situations the diet alone cannot provide enough vitamin D to avoid the risks of rickets in children, osteoporosis in the elderly, nor enough iron and vitamin B9 to avoid them. risk of anemia in pregnant women (in 2005 the situation is seen differently for pregnant women, vitamin B9 being given in peri-conception especially for the prevention of neural tube defects and systematic iron supplementation during pregnancy is not recommended – a good thing when we know that only 23% of women of childbearing age have low ferritin, that iron is pro-oxidant, that oxidative stress is increased in pregnant women and that iron antagonizes zinc,missing in 100% of them and much more important in particular for in utero growth).
But the micronutrient supplements that children and pregnant women receive are still very fragmentary. Dietary surveys and clinical studies show that in children and pregnant women there are significant discrepancies between intakes and requirements for many other micronutrients.
These circumstances therefore require specific advice on the frequency of consumption of certain foods rich in vitamins, minerals, fatty acids and essential amino acids and appropriate supplementation.
There are many other circumstances and many factors leading to an increase in micronutrient needs which are not taken into account in the recommended intakes: sport or high physical activity, stress, toxins, pollution, risk factors, diseases, treatments, climatic variations, dietary imbalances …
Runners Sport increases the need for magnesium, several B vitamins, vitamin C and vitamin E. Long distances have an increased need for irons: if their physical activity takes place at altitude, the required amount may still increase for some micronutrients.
Any type of stress can induce urinary loss of magnesium
Stress induces an exit of intracellular magnesium which increases the urinary losses in this mineral.
This is true, whatever the type of stress: linked to intense physical effort, a sudden change in temperature or altitude, noise, psychological tension, trauma, an operation, etc.
Moreover, this release of magnesium from cells is accompanied by an entry of calcium and iron, a phenomenon which intensifies the emissions of free radicals and leads to the destruction of vitamin E and polyunsaturated fatty acids [63], this which amplifies the cellular losses of magnesium (still a vicious circle).
Author Jean-Paul Curtay
