Magnesium absorption

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The Magnesiumresorption , so the absorption of magnesium in the body is carried out, mainly in the upper small intestine . About 40% of the magnesium is absorbed from food. The absorption of magnesium takes place via ion channels such as TRPM6 and TRPM7. On average, about 0.15 to 0.2 mmol of magnesium per kg of body weight is absorbed, of which about 60% is excreted with the stool and 40% with the urine. 99% of the magnesium is in the cells (intracellular), only about 1% in the extracellular fluid and here about half is in free form and others are bound to albumin and complexing agents. About 75% of the magnesium content in the blood is ultrafiltered in the kidney and 50–60% of this is reabsorbed in the thick part of the ascending loop of Henle . The absorption of the absorbed magnesium into the cells is higher, the greater the magnesium deficiency in the organism. In addition, absorption is significantly higher if smaller amounts are administered to the body throughout the day. High doses of magnesium (250mg and more) can bring the natural proportions of the nutrients out of balance. B. impair the absorption of calcium and zinc. (On the other hand, high oral calcium doses increase a magnesium deficiency.) For this reason, too, the Federal Office for Risk Assessment warns against overdosing and specifies a maximum amount of 250 mg.

Influencing factors

The absorption of magnesium in the small intestine is increased especially in the presence of protein and vitamin D as well as somatotropin and parathyroid hormone . The reabsorption in the kidneys is increased by parathyroid hormone and magnesium deficiency and decreased by somatotropin, aldosterone , ADH and thyroid hormones . The physiological and basic active ingredient magnesium citrate is metabolized particularly well, since citrate (citric acid) is naturally present in the body as an endogenous binding substance. In addition, the citrate anion has an alkaline effect in the metabolism and contributes to the regulation of the acid-base balance.

Individual evidence

  1. ^ A b c Hans-Konrad Biesalski: Nutritional medicine: according to the nutritional medicine curriculum of the German Medical Association . Georg Thieme Verlag, 3rd edition 2004, ISBN 9783131002938 , p. 163.
  2. ↑ GA Quamme: Recent developments in intestinal magnesium absorption. In: Current Opinion in Gastroenterology Volume 24, Number 2, March 2008, pp. 230-235, ISSN  1531-7056 . doi : 10.1097 / MOG.0b013e3282f37b59 . PMID 18301276 .
  3. ^ Walter Siegenthaler: Clinical Pathophysiology . Georg Thieme Verlag, 9th edition 2006, ISBN 9783134496093 , p. 181.
  4. ↑ Christian Hick, Astrid Hick: Intensive Physiology Course . Elsevier, Urban & FischerVerlag, 6th edition 2009, ISBN 9783437418938 , p. 206.