Today we will talk about Magnesium and in particular its FUNCTIONS, DEFICIENCY SYMPTOMS, EXCESS, FOOD SOURCES and RECOMMENDED LEVELS.
As many of you already know, magnesium is one of the most popular mineral salts in dietary supplements. It performs many important functions for the body and, in athletes, its deficiency can manifest itself quite easily.
Magnesium is considered a MACROELEMENT; this classification, which also includes other mineral salts such as CALCIUM, PHOSPHORUS and POTASSIUM, indicates that its nutritional needs DO NOT exceed 100mg per day and that its content in the body is higher than the more modest one of the MICROELEMENTS.
In fact, the collocation of magnesium between MACRO and MICRO (or OLIGO) elements is still under discussion. This means that, based on the popular source, this mineral salt can be cataloged as the MOST MODEST of the MACROELEMENTS or the MOST IMPORTANT of the MICROELEMENTS.
In the adult human body, magnesium is present in about 20-28g, of which more than half in the bones and the rest in the cells; only a small part, about 1%, is diluted in the extracellular fluids, therefore in the interstices and in the blood plasma.
The functions of magnesium are different and, while in humans the most significant are the CELLULAR REACTIONS, in plants it is a fundamental constituent of chlorophyll.
More precisely, in our organism, magnesium participates in many metabolic processes such as:
- the synthesis of lipids, the synthesis of proteins and the synthesis of nucleic acids (ie DNA and RNA)
- and cell membrane transport.
On the other hand, the small percentage of magnesium diluted in extracellular fluids is still extremely important, since it allows the proper functioning of the nerve impulse between the nerves and between the nerves and muscles.
Finally, as can be deduced from its prevalence in the skeleton, this mineral contributes to bone development in partnership with calcium and phosphorus.
The absorption of magnesium occurs in the intestine with the ACTIVE TRANSPORT and DIFFUSION systems, but the amount retained is INVERSEALLY proportional to its concentration in food. In practice, the more you eat, the less you absorb!
Then, remember that the absorption of magnesium is also influenced by certain metabolic factors:
- high concentrations of vitamin D in the blood FACILITATE its retention
- while large portions of calcium, phosphorus, phytates and long-chain fatty acids, as well as ALCOHOLISM and DIARREA, REDUCE absorption.
Ultimately, taking for granted a normal diet and a desirable level of physical activity but not SPORTS and VERY INTENSE, the maintenance of the right levels of magnesium in the blood are mainly determined by: BY THE CAPACITY OF ABSORPTION OF THE INTESTINE and of the RENAL FILTRATION, constantly in balance with each other.
It is interesting to discover that: the excessive REDUCTION of magnesium in extracellular fluids STIMULATES the release of a SPECIFIC hormone (ie PARATHORMONE) which in turn determines the reduction of urinary excretion of magnesium and promotes the release of that contained in the bones.
In fact, given the body's ability to store it within the skeleton, achieving CHRONIC and PROGRESSIVE magnesium deficiency is NOT such a frequent occurrence. It could occur in cases of general malnutrition, kidney diseases, intestinal diseases or certain types of hormonal disorders. ONLY in this case, the following could occur: the alteration of the metabolism of calcium, sodium and potassium, with muscle and cardiac TETANIC compromises.
Conversely, the FAST and MOMENTARY reduction of magnesium levels in the extracellular compartments is much more frequent. This happens above all in ENDURANCE SPORTS, that is the FOUNDERS, who show EXCESSIVE sweating during the performance. In this case, the intervention of the parathyroid hormone is NOT fast enough to restore magnesium levels in the blood, with symptoms such as: fatigue and reduced muscle efficiency, and cramps.
As with deficiency, assuming CORRECT metabolic functioning, excess magnesium is an almost impossible possibility. It can be obtained ARTIFICALLY by taking magnesium-based laxative drugs which, however, cause diarrhea with the consequent expulsion of excess minerals.
The only possible occurrence of HYPERMAGNESIAEMIA, or too high magnesium in the blood (once again excluding kidney diseases) is INJECTION; this, potentially lethal, manifests itself with nausea, vomiting, low blood pressure, heart abnormalities and nerve conduction abnormalities.
Magnesium is an almost ubiquitous mineral among foods of natural origin and unprocessed, although meat, fish products, milk and derivatives provide much less than others.
Magnesium is typical of vegetable products; it is abundant in legumes, whole grains, oil seeds and green leafy vegetables.
To conclude, remember that up to 80% of the magnesium in CEREALS is REMOVED with refining, which is why bran is ABSOLUTELY the richest food in magnesium. Be careful though! Excessive amounts of fiber and chelating molecules such as phytates can hinder the intestinal absorption of magnesium; it is therefore advisable to consume whole grains, rather than refined ones and bran separately.
In the diet of Italians, which we remember as TENDENTLY Mediterranean, the magnesium intake is about 250mg per day, of which ¾ with plant foods.
It is also contained in water but its concentration in various liquids is extremely variable and poorly quantifiable.
Remember once again that magnesium taken with food is NOT fully absorbed and, in addition to factors that depend on the body, certain nutritional components (such as phytates and excess dietary fiber) reduce its BIOAVAILABILITY; on average, it seems that in the diet of the Bel Paese the proportion of well absorbable magnesium is between 20 and 60%.
From the research carried out, it seems that the intake of SUFFICIENT magnesium can be between 3 and 4.5mg per kilogram of body weight, or about 210-320mg per day. On the other hand, the COMMISSION OF THE EUROPEAN COMMUNITY, in 1993, established a safety interval of 150-500mg per day. Obviously, from what has been said about the needs of athletes, the minimum intake can vary significantly with sweating, which is why IN THE NEXT VIDEO we will go into more detail regarding MAGNESIUM INTERGETERS.
