Generality
General information on magnesium
In nutritional terms, magnesium means a macroelement of mineral origin - more precisely a metal - with the symbol "Mg" and atomic number 12 and shape. Note : in food and in the human body, magnesium is always present in the form 2+ (Mg ++).
Magnesium is an essential nutrient for the life of all cells, as it constitutes over 300 types of enzymes and has a particular affinity towards phosphate groups. It interacts with fundamental molecules such as ATP, DNA and RNA. Its presence in cells is positively correlated with that of potassium, while it appears to compete with calcium levels.
The body contains more than 22-26 g (about 0.35 g / kg) which is equivalent to 0.34% of body mass. Of these, 60% are found in bones - within hydroxyapatite - 39% are intracellular - 20% in skeletal muscles - and 1% are extracellular; overall, 32-35% of total magnesium is complexed to proteins - such as enzymes - and nucleic acids.
In the blood, it can be detected either dissolved in the liquid fraction or in the corpuscule. Normal serum levels correspond to 0.7-1.0 mmol / liter - 1.8-2.4 mEq / liter - and tend to remain in homeostasis - due to a twofold regulation involving absorption and excretion. An excess of magnesium in serum, unlikely in healthy people, is called hypermagnesemia, while the deficiency - instead frequent, even if asymptomatic of slight entity - is called hypomagnesemia. Magnesium insufficiency has various repercussions, including for example muscle weakness and cramps. Hypermagnesemia can be very serious and, despite mainly affecting those suffering from kidney diseases and taking drugs with magnesium, lead to death.
Magnesium absorption occurs in the small intestine and is optimized by hormonal and metabolic factors, magnesium deficiency and some meal characteristics; it is mainly hindered by diarrhea, certain nutritional factors - chelating agents, excess phosphorus and calcium, etc. - by some drugs, pathologies, and alcoholism. On the other hand, excretion is mainly determined by urine through kidney filtration and sweating - the latter has variable and subjective importance.
In pharmacology, magnesium is used to produce laxatives, antacids, remedies for nervous disorders and eclampsia.
In the next section we will focus on the most important food sources of magnesium, which are mainly made up of products of vegetable origin - but also those of animal origin, such as meat and fish, contribute to the achievement of needs. Recall that suspecting magnesium deficiency can be very useful to take specific supplements, preferably in combination with potassium and little sodium; a possible role of the latter in reducing the climacteric syndrome has also been hypothesised.
Food
| Magnesium rich foods | Quantity (mg / 100g) |
| Bran | 420 |
| Dark chocolate | 292 |
| Almonds and cashews | 260 |
| Cocoa | 192 |
| peanuts | 167 |
| Hazelnuts | 160 |
| Pistachios | 158 |
| Dried walnuts and chickpeas | 130 |
| Corn | 120 |
| Beta | 113 |
| Milk chocolate | 107 |
| Brown rice | 106 |
| Dried spices | 82 |
| Lentils, cooked chard and cooked spinach | 80 |
| Artichokes | 60 |
| Whole grain bread | 60 |
| Pasta | 57 |
| peaches | 54 |
| Parmigiano | 44 |
| Chicken and turkey | 40 |
| Zucchini | 40 |
| Cauliflower and broccoli | 30-35 |
| Bananas | 31 |
| Cheeses - various | 20-30 |
| Cooked potatoes, fennel, polished rice and pasta | 20-25 |
| Red meat - various - and pork | 20-25 |
| Fish - various | 20-25 |
| Peppers, carrots and tomatoes | 15 |
| Plums and oranges | 11 |
| Apples and pears | 10 |
Data source: INRAN, National Institute for Research on Food and Nutrition
requirement
| Age' | Magnesium requirement (mg / day) |
| Infants up to 6 months | 30 |
| Infants from 6 months to 1 year | 75 |
| Children 1-3 years old | 80 |
| Children 4-8 years | 130 |
| Children 9-12 years old | 240 |
| Boys 13-19 years old | 410 |
| Girls 13-19 years | 360 |
| Adult men | 420 |
| Adult women | 320 |
| Pregnant women | 360 |
The daily magnesium requirement for adult humans amounts to 300-500 mg and, given its distribution in numerous foods, is apparently easy to satisfy. It must however be considered that a significant portion of magnesium is lost due to the refining of cereals, the preservation and cooking of food. It is also estimated that only 30-40% of the magnesium ingested with food is actually absorbed; on the other hand, in certain "unfavorable" situations, this percentage would even fall to 20%. See also: ZMA: zinc magnesium and vitamin B6.
